Faulty phone from Orange, Apple says tampered phone so no warranty cover.

This question is for UK ONLY. I received a new iPhone 4S from Orange in March 2013. Everything was working well and I loved my phone until it developed a fault. It started with horizontal lines then vertical lines, that slowly the screen faded. Took it to an Orange store and was told that only Apple deal with iPhones. So I took it to the Apple retail store in Trafford centre. The technical expert took a look and agreed to replace it. He said that he needed to get the serial number and took the phone inside. On return, he asked where I had received the phone from, to which I answered, Orange. He then informed me that there was evidence of the phone being tampered with, the serial number had been scratched off and some screws were missing. He said that because there was evidence of tampering, the warranty was invalid. He advised me to take it back to Orange. So I took it to the Orange store opposite, they said that as I had received it from Orange direct, I needed to contact them.

I contacted Orange and was passed from 1st line phone help to technical advisor who after a lot of questioning and I presume, head scratching, passed me onto an Apple advisor, he was very helpful but eventually (after checking with head office) returned the same verdict of invalid warranty.

I rang up Orange again only to be told that Orange could not do anything because they are tied in with Apples terms and conditions, they accept that their records show that I have been using the iPhone from the day I received it. I went back to the Apple store again and talked to a manager as advised by the Orange customer service, the Apple manager was as helpful as he could be but again stated Apples position. He agreed to talk to the Orange customer service but it took over an hour to get hold of line manager who initially accused me of possibly tampering with the phone and than possibly some one known to me doing the same.

I am at the end of my tether at present and asking for any help or suggestion in order to resolve this issue. It present I seem to be going round in circles and wonder if anyone has had the same or similar problems.

Thanks in anticipation.

Sumit.