Motorola
Motorola ROKR Z6 IMEI invalid

I purchased Motorola ROKR Z6, 2 years back all was well untill 30-11. But after that it is dead no Operater SIM working on it, It seems that Motorola sets IMEI no is invalid. I have receipt of the product with IMEI no stating on it, when I contected with store where I brought it, they said goto to Motorola Service Center, and Motorola Service Center is not responding well, today (1-12) whole day my mobile is dead. who is going to resolve it??