Airtel — Number disabled, error during recharge, customer care not providing complaint reference

Hi,
My mother ported her Vi number to Airtel in early August. She went to Canada later in August and left her Airtel number with her sister in India. After two months, her Airtel number stopped working completely and gives an error "Not Registered". Her sister went to Airtel store to get it checked but they said that sim is bad and no longer works. They refused to replace the sim. The number is 15 years old and is the primary and only contact that everyone has. It is also linked to her bank accounts and all other government services where phone number is mandatory. She cannot pay anymore bills because she cannot get OTP without getting the number fixed.

I also contacted Airtel through Facebook and Twitter, but no one has been able to tell me the problem and how to fix it. They keep on asking me to provide an alternate number for them to contact. I live in Canada so I provided them my Canadian number. They always come back by saying that "They tried to call us but couldn't reach me". I have heard the same response so many times when I didn't receive a single call from Airtel. I also asked them to provide me a number so that I can call from here but they did not provide that either. I asked to provide proof of calls that they made and they did not provide that either. I asked them for complaint reference number and they haven't given me anything even after asking more than 10 times.

Customer Care on Twitter told me on 24th November that the validity of the pack has expired on 20th November and I should recharge. I did an online recharge of Rs 49 but got an error "Sorry! Your request could not be processed. Please try again later". The amount is already debited from the account. My mother is so stressed because of this and it is so annoying to hear the same response over and over again from Airtel.

Here are the details of the number:
Phone # [protected]
Owner - Manjit Kaur Khosa
Email - [protected]@gmail.com

I can be reached via email at [protected]@gmail.com or anyone can call me at +1-[protected].