Shady & they underpay you. (If they even pay)

I have only just managed to resolve my issues with this company. I sent them my iPhone 6S 64GB and I had an email confirming they had received my phone not long after.
The iPhone had a cracked camera lens but besides that it was in perfect working condition and the only reason I wasn't using it myself was because I had just recently had a new phone on contract. Regardless, I still stated the phone as "faulty" because it must be claimed as faulty if there are any cracks.
I didn't hear anything from this company for several days so I sent an email asking what they have determined about the phone. I heard nothing back. A day or two later I sent another email but this time through a query on their website. I still heard nothing from them. A week passes since I got their email telling me they received my phone and I became impatient. I email them again and say I need to know what is happening (phonecalls were also unsuccessful as they don't answer). I let another day pass and by then I was furious. I said if nothing was resolved soon I would be taking it up with trading standards and low and behold they responded relatively quickly. They took some time but quoted me £80 instead of the £122 they originally said. They told me the phone is "beyond economic repair" which is not true as the only thing that was wrong was a cracked camera lens. Plus if a phone is registered as faulty then you should know that it has some issues. If I had wanted £80 then I would have went with the better known and more reliable companies. I declined and said I wanted the full amount paid by the end of the week or they can just send it back to me (which they were charging me £6.99 for!)
They got back to me the day later with another offer, this time for £100, saying that they have bumped up the offer "as part of a one time customer satisfaction" which I don't buy at all because it seems like everyone is getting the same treatment. I have agreed to this price but I am still not happy and almost didn't agree out of principal. I let them know I will warn anyone about them and leave negative reviews so others can know what I went through. Over a week and a half of silence, misquoting, changing offers and just all out lies. Do not use this company to sell off your old phone. They use their high quoted prices in comparison to other websites to entice you to sell to them. But when it comes down to it they will actually offer you less and take way more time than any other company out there. If these people are con-artists then they are the worst con-artists I have ever seen. I just believe they are incompetent, shady and they try to chance underpaying by using methods like "the phone is broken beyond repair" or "there are damaged pixels on the screen" as a way to fool some customers who might be none the wiser. Again, avoid this company at all costs.