Complaint regarding internet service from excitel

I applied for the internet services of Excitel company from internet wifi. Everything was good when I was paying them monthly.  Then I payed in advance for 1 yr and I started having frequent disconnection. No one comes to address the problem for 1 whole day often. They just forward an automated mail and message when I try to complain. In less than 3 months I have faced 10 major disconnection. Administration blames it on their local business partners but never solve the issue. People in my locality who are paying monthly doesn’t face any such problem.  Ground team and technician never pickups the phone and are always ignorant. Company is saying they won’t refund me if I want to discontinue.