Airtel — Unsolicited Internet bill

I have been an Airtel Internet customer since 2022. I have been paying my bills in advance on a six monthly basis. In August 2023 I paid my six monthly advance payment to last until February 2024. In September 2023 Internet stopped working. I file d a complaint. They said it will be back on but did not happen. In October 2023 I called Airtel and spoke to them. Still no solution. In December 2023 I filed a complaint again and asked them to stop my Internet services completely and refund the money. I was answered it shall be done. Then In February 2024 I was hit with a bill they are overdue. With much effort after trying to explain what happened they waived the excess bill and still did not stop my Internet. In March 2024 I was hit with my monthly bill again with fines. I wrote to Airtel again why am I getting bills when Internet should have been stopped. I did not get a reply until 16/4/24 which they mentioned my final bill is Rs 2100 for two months with fines. I have requested them again and again to stop my internet services and to waive the bill for the service I am not using and to refund my money from the past. They are not addressing the issues and still keep saying I have to pay the bill. Now on top of this they have acknowledged that they have stopped my services but the bill keeps generating until this day and in their reply they are mentioning I am still liable for the bill that is getting generated. I cannot understand their logic nor does it make any sense.
I am requesting that all my bills are waived for the service I have not been using, refund my money from the past since October 2023 - February 2024 and stop Internet services immediately.