Wren rubbish customer service

I do not really know where to start. My wife and I arranged for Wren to quote for our kitchen, after we booked the home visit we thought we would read the reviews online and found them to be extremely poor. We called Wren Chelmsford and cancelled the appointment. A few days later I had a call from one of the many branch duty managers. She convinced me to go back into store and discuss our kitchen with them. Whilst in there she said she could not promise that we would not have any issues but stressed that all the problems Wren had been having were now resolved and a thing of the past, she confidently said she was 98% sure that everything would be fine, but if we did have issues she would sort them without delay or hassle and she would see the order through from beginning to end.
Well to start with I was impressed by their speedy delivery, whilst checking through the items I noticed that a corner post was on my invoice but was not on the delivery note. I called the manager and sure enough she arranged for one to be delivered a couple of days later from another branch. This arrived twisted and bent but I managed to get over it as I didn’t want any further delays.
When unpacking the units I noticed that 8 of the base units were not pre drilled for the feet, which does not sound like much but the lugs on the feet locate and should position the feet perfectly for plinth to be located in the correct place, they also add to the strength of the feet. I called Wren to discuss this and was told to cut the lugs off and just screw them to the base, I tried to explain that it’s not that straight forward and was told it was. I asked to speak with the area manager and he advised me to do the same thing, I explained that it means I have to measure all of the units / feet to ensure they go in the correct place and he said it wouldn’t take very long. He offered me £50 compensation for my time and I told him it’s not enough, he then increased it to £75 and we ended up settling on £100. During the conversation he told me it would take 5 days for the cheque to arrive, that was over a week ago and still waiting.
When ordering our kitchen we also ordered the sink from Wren, I think it was about £450. When unpacking it I noticed it was bent, Wren collected about 10 days ago and when I chased the refund yesterday they advised me that the refund has been processed. But I do not know how as the money is not back in my account and I do not even think they have my bank details.
Whilst unpacking the filler panels some of the paint on them was damaged, I managed to use them but was frustrated that they were damaged to start with.
Our designer had designed our kitchen to house a 260mm service gap behind our row of sink units, this was because we have underfloor heating pipes and a pump which we did not want within our units. On the plan it showed that we had to cut the service gap off the 5 drawer unit so the cupboards were able to go back far enough to accommodate this. Now he must have got the measurements wrong somewhere because even though we have cut the service gap off the gap behind the units is still 375mm which means we have had to use a 900mm worktop and my wife can’t reach the back of it.
On the same run of units there is a corner unit which sits next to the 5 drawer unit, once the drawer unit was cut down the corner unit protruded past it which also meant it also had to be cut down. Now this corner unit has high gloss panel and door. When I called Wren to discuss this I was told by a manager to cut it down, I tried to explain to him that you can’t just cut it down because the panel may splinter and leave a rough edge plus you will have to actually cut the carcass down because there is no service gap on it. He said he will visit to have a look, whilst he was at my home he said just cut it down I told him I was not prepared to cut the high gloss panel and he replied and said he would take it away and arrange for it to be done. A couple of days later he sent the cupboard back with a driver, my wife asked the driver to put the door on so he did. At this point she burst into tears as the side panel had not been cut and the door stuck out way past the unit, she called me at work and I called him to ascertain why it had not been cut and he told me I had to do it! I took the decision to cut the panel and sure enough it splinted, I had to make up another panel to go in its place.
During all of these issues and making several calls to the branch it became evident that Wren had supplied too much product, 2 extra filler panels and 2 extra cornices I think the value was about £300-£400. I asked both the guy who visited my house and the duty manager to collect them and refund, both told me to leave them until I had finished and they would arrange for them to be collected and refunded. I have since been told "In the terms and conditions it states that it is your responsibility to check that you have the quantity and conponents you require."
So their designer gives me too much product and they will not collect and refund.
So to the next problem, our island, the designer designed our island over 910mm wide, the problem being is that Wren only do a 900mm worktop so by the time you have added 20mm either side for the worktop over hang the work top should be min 950mm. On the drawing it does clearly state that I had to once again cut the service gap off the back of the corner unit to be able to use the 900mm worktop. BUT there was an issue with that, and that is there is NO service gap on the back of Wrens corner units. So I once again called Wren and they ONCE again told me to cut the high gloss panel and carcass down to accommodate their errors. I told them I’m not doing this and I was going to order new larger replacement work tops and required them to collect the ones they had supplied which are too small. Their response has been they will not credit or collect, even though this is their error they are not doing anything about it. So the upshot is Wren say if it doesn’t fit "CUT IT DOWN", if we have supplied you too much stuff, "TUFF NO REFUND" if we get our measurements wrong "CUT IT DOWN" If you want a refund "we won't refund" if we have forgotten to drill the holes "Do it yourself"