Thanks for the reply. i just found out that the o2 service is not as good as before. all the service centre number i tried was engaged. thus, i just realised that o2 ( the pda selling division of o2 group ) had been taken over by MWG, which i dont know what company is it.

i asked MWG, how long will it take to repair my o2 which is still under warranty, and the answer is 3 weeks.