HTC — Technical problem

Address:

Thane, Maharashtra, 400604

No network issue, mic not working, touch is very hard, very hang, when call coming that time mobile hang. service centre is not supporting for repair & they are unable to solve or resolve complaint of my mobile.i already given my mobile in service centre but they also not able to solve the compalint. and my mobile was still in their centre for repair, so please you help me to solve my mobile issue or replace my mobile .. the service centre in vashi are not helping me to solve or replace my mobile.