Airtel - Nonrenewal of Phone Number

I received a SMS from Airtel stating that my mobile number would be deactivated by **th May if I do not update my Visa details by the said date. I had sent the required documents on *th May to ***@airtel.com as mentioned in the SMS. I did not receive any reply and on **th May I resent the document to the same email ID. However, I still did not receive any response. I then contacted @Airtel_Presence on Twitter on May **th. They gave me a link to WhatsApp (+************). I contacted them via WhatsApp on the **th May but again no response. On **th May I found on Airtel website that I could escalate to appellate.tn@airtel.com. I sent the documents to them and told them to expedite as my number was going to expire on **th May. However, no action was taken and my number has now lapsed. They are now asking me to be physically present at an Airtel outlet within * weeks to reactivate my number. I am a Malaysian with OCI and currently in Malaysia. The number was renewed in February for Rs *,***. It is just not the inconvenience of the amount but so many services are tied to this number including my banking. They are saying I have to be physically present to reactivate within * week of deactivation. I pleaded with them saying I am in Malaysia and that it is their fault for not extending my Visa expiry in a timely manner. My appeal is falling on deaf ears though. Please help.