detects only 3G signal but doesn't read 2G signal

My N8 which I got it from Canada with Rogers network, worked well for an year. Then suddenly from one morning onwards it doen't receive or detect 2G signal.

It works and detects only in 3G signal area. All the tips and tricks had been followed but no use. I took it nokia care and even they couldn't fix it and the reason they said was that I am using it in India but not in canada. So, they couldn't fix it.