Airtel — call drop & unable to use internet while in a call

Address:

Hyderabad, Telangana, 500008

I am from hyderabad from the last three weeks my voice calls are getting dropped for every 10-12 minutes along with that i am unable to use mobile data while i am speaking over phone.

Initially i though it was my handset problem and i have contacted corresponding service center and i have even performed restore factory settings on my handset, as the issue still persists i put my sim in another handset and observed that same problem is replicated in that handset as well.

This is annoying me, please fix my network issue.

Thanks
Venkat