Mts — Mts data card speed issue and customer care not respond

Address:

Chennai, Tamil Nadu, 600011

I had taken mts data card internet connection & on mid of last year ( aug 2015 ) due to lots and lot of issues in speed, i mailed to disconnect to customer care but no reply, so again and again i mailed them and to know the procedure of closing & that outlet guy checked my connection status & told me to clear my outstanding till, so i told them to check why i had the connectivity issues, they replied one of the customer service engineer will come and inspect, but till day ( apr 14 / 2016 ) no one came to my home. But i have received several calls and messages, to pay the balance, now they are threatened me that criminal offence will be charged against me. My question is why????. My question is i had paid my billed before i got the issues. I have emailed them from 11/10/2015, but till date the bloody hell was not come for inspection. My mts number is [protected]. I need the proper answer. Or any one help me to how to file a complaint against them.