Airtel — bills on wrong email id

Address:

Canias ERP Pvt Ltd, 426, 4th floor East Wing,, East Wing, Amanora Chamber, Amanora Mall, Hadapsar, Pune, Maharashtra, 411028

We have been writing an email to Airtel customer care and also spoke to them when they gave a call to understand the issue. We explained the issue and requested to change the email ID due to wrong email id we are not receiving bills on time. We also informed them that the email id on which Airtel are sending bills does not exist.

Even we have submitted a letter on letter head with all the details required.
but still are not bothered change the email ID and continuously sending the auto generated mail.
Can some one help me in resolving this issue.