Airtel — Bill generation even after deactivation request

I have raised disconnection request of my airtel broadband through customer care as we were moving to new town and there is no airtel line over there excutive they said request raised and my connection will be deactivated in 7 working days

I dint recieve any sms I ignored as j thought it may be some network issue

Due to Personal emergency I missed to check whther it is deactivated or not..i dint get any calls from airtel tooo

Later two months I have received two months bill with late payment.

I called customer care and asked for some waive off as my usage is 0 % but they denied and I asked to take the request atleast now
They said we raised request but still I dint again any sms or mail
I called them again.. Other excutive saying nothing has been raised may be some system error.
It is really frustrated due to their careless two months is on due
I mailed airtel regarding waive off my due am yet to hear back.