Hi, I have an iPhone 3GS on O2 which I received in February. Didn't take out insurance 
About 1 month ago, I dropped it, which smashed the screen, which I have subsequently had repaired by a "local" mobile phone shop.
The phone worked perfectly, but 2 weeks ago, the signal began to become intermittent - it never goes above 2-3 bars and often loses signal totally.
I had it sent back to O2, who advised it's been misaligned (?) and would cost £300-00 to repair, which I declined.
The girl in the O2 shop advised me to take it into the Apple Genius Bar and see what happens - do they replace faulty items of this nature?

About 1 month ago, I dropped it, which smashed the screen, which I have subsequently had repaired by a "local" mobile phone shop.
The phone worked perfectly, but 2 weeks ago, the signal began to become intermittent - it never goes above 2-3 bars and often loses signal totally.
I had it sent back to O2, who advised it's been misaligned (?) and would cost £300-00 to repair, which I declined.
The girl in the O2 shop advised me to take it into the Apple Genius Bar and see what happens - do they replace faulty items of this nature?