Tata docomo 3G dongle not working

I am using Tata 3g Postpaid Dongle. From past 3 days my internet is not working and my dongle is not connecting. I have registered complaint regarding this to Tata Customer Care too but they are not responding to me. Each month at the end of my usage cycle internet stops working and my data usage is wasted. Tata Service suck big time and they surely don't pay any heed to customer's problems. Everytime their representative says that there is some issue with the network and your problem will be solved in 2 hours but its been 3 days and they don't do anything.

Complain here: pgportal.gov.in