Customer experience at Optical Express worst of my life

This is by far and away the worst customer service I have ever experienced from any company in my life. Here's the story as to why Optical Express are horrifically bad and should be taken out of business:

Start of Jan 2014: go to get a free eye test to see if I'm suitable for laser eye surgery. I'm not. 
Mid Jan 2014: go to get a new pair of glasses in the London Monument store. Find a suitable pair and order them. Sales assistants are rude and unprofessional. 
End Jan 2014: receive new pair of glasses (one week after they said they'd arrive). When picking them up, notice a sign on the wall saying you get a free pair of glasses if you spend over £100, which I did. Enquire as to why I wasn't offered this. Lady asks in a condescending manner "oh but do you need another pair?". Finally, after some discussion, they agree to give me a second pair. As soon as I leave the store I realise I can't see 5m in front of me. 
End Jan-start Feb: try to get used to my new glasses, but fail. They give me huge headaches and I can't focus long-distance. Also they keep falling down my nose and my eyelashes bash up against them every time I blink. 
Start Feb: get my second pair of glasses. They also don't fit properly. The sales assistant heats up the arms to bend them in a bit. 
Mid Feb: glasses still causing headaches and still can't wear them as they're falling down my nose. Relocate to Canterbury and go to the Canterbury store to get them to alter both pairs of glasses so they don't fall down my nose. They bend the arms so much that they pinch really badly behind my eyes. 
End Feb: ask for a refund on the glasses as they're not wearable. Am told I can't get a refund as it's not their policy. I then state by law they have to as the product is not fit for purpose and I will pursue this in a court of law to get my refund. They say they will do an eye retest and will allow me to choose a different set of frames. I reluctantly agree. 
Start March: have to go all the way back to Monument store (London) to get eyes retested. Am told miraculously that my vision has somehow improved in one eye from +4.25 to +2.25. This is physically impossible. The optician can't explain it either but says that's just what the reading tells her. I find another pair of glasses that do actually fit and get new lenses put in. They will be sent direct to Canterbury store so I don't have to travel back to London to get them. 
Mid March: glasses still not arrived. Call them up, they say they were lost in the post. They reorder another pair to get sent direct to my house. 
End March: new glasses arrive. Can't see long distance again because the lenses are the wrong prescription. Ask for a refund. Finally they agree. 
Start April: go back to Canterbury store to process refund, who have not been told that I need one. Hand glasses back to them and am told I might have to wait 28 days for a refund to be processed (although they expect customers to pay the full amount of money before receiving a pair of glasses?). 
May: finally, after 5 months of waiting and hassling them, I received my refund.

What a poor excuse for a company. I would advise everyone against going to Optical Express. I've since gone back to trusty Specsavers, who did and eye test that confirmed my usual prescription. Really should've just gone to Specsavers all along. Lesson learnt: STAY WELL CLEAR OF OPTICAL EXPRESS!!