Civil case being filed for non-payment of bill by internet provied

A civil case has been filed against me by the internet service provider for non-payment of bills. I have had the connect for about one-year and few months and have paid all the bills before due dates. In the month of June, they (internet service provider) asked me if I wanted to upgrade my connection to 4G. I denied citing poor network. The number of calls increased asking me the same and one customer service personal explained as to how my present connection would be barred and the only way to continue the having the connection was by upgrading it to 4G. And for this, I was supposed to go in search of their outlet any where in the city, buy a new dongle, a new adapter, submit a copy of my details, all in all, the process similar to getting a brand new connection. I again denied upgrading and requested the customer care personal to end my connection. I even wrote a email to them stating the same on July 13. Just that evening my connection was barred. I waited for their reply in vai