Micromax — Did not received the handset given for service even after 48 days

I'm Gandhi . My son G.Karthick has given my mobile(micromax a350) for service in a service centre in Coimbatore .the service centre had told that the mobile will be returned within 10 days.But even after 20 days they didnt return the handset .so I called them but their reply was too poor .They told to wait for another ten days.Again we waited for ten more days but there was no reply from the service centre.so I called micromax customer care and filed a complained . Mr.ravikumar promised that the handset will be returned within a week. But still they was no reply even after 10 days and so we kept on calling the customer care and enquired the status of the device.whenever we called their reply was to wait for 20 more days . I can't wait anymore believing that the device would be repaired.i need a replacement of my device as soon as possible.Almost 2 months are past please provide a replacement for my device. I gave my mobile to xplus communication, Coimbatore .my job sheet no. Is s[protected]