Nokia :: 7230 Hairline Cracks On Top Casing - How To Remove

I have had a Nokia 7230 for about 3 months or so. In the last few weeks 2 hairline cracks have appeared in the top right hand corner of the top half of the phone. In the corner where the light illuminates to inform you of a call or sms. There are also another 3 cracks forming in other parts of the same casing.The phone is well looked after and has not been dropped or knocked. I have spoken to O2 who I bought the phone off but they have advised that their technicians will view it as physical damage and just return it. I was also told that this is not common at all. It appears that the thin silver coloured band on the top part of the phone has a weakness.