Connect Broadband — Ignorance of written application regarding plan change

Address: Ludhiana, Punjab, 141008

I am using connect broadband wifi connection from last 4 years at ludhiana. I had to face lots of problems with their service. I filed lots of complaints on customer care service phone about my wifi connection not working properly but no body had taken any action. One of customer care person suggested me to change the plan into higher plan. I changed the plan accordingly but still the problem was same. Another person came and he suggested to change the wifi router, I changed that also. No body had solved the problem from last one and half years. Every month I gave thousands of rupee but problem still persist.
Three months back I gave written application to the connect service center regarding change of my broadband plan, but they forgot to forward that further as they told me when I asked them, and I had to pay 2500 for two months again as without my fault because of their negligence. Now they are again asking for bill for two months, even I didn't have network access in that months.