Customare care cheating on disconnection request

Hi , as I was relocating to US i asked my neighbor to disconnect the connection and then they confirmed it through a call. My broadband no was removed from acc and was not working after two days. But they start to call my neighbors no and demand payment for 2 months. When I called the service from US hey say my newborn didn't confirm. There was no disconnection request which is wrong. If so how come they disconnected and removed number from my acc in days after the call? How can I get the call recordings made for the disconnection request? They say they didn't disconnect and it was removed from acc by mistake. Disconnection request made in may 15th connection disconnected on May 17th and removed from my acc. But they are harassing my neighbor to pay the bill. How can I resolve this and get the airtel Customare care recordings