Airtel MNP problems

Recently I submitted a request to Airtel to port my number from Airtel to BSNL. After 4 days I got a message from BSNL saying that my request was rejected by Airtel due to legal reasons. When I called the help desk at 121 they said since my balance was negative they rejected the porting request.

1. When I Submitted porting request my balance was 10 Rs.
2. No call was made nor was any message sent. How did I get into negative balance then?

After lots of talking the call centre guy finally conceded that the 10 Rs debit was wrong and agreed to refund it. They did refund the money immediately. But now I have to resubmit the porting request, wait for 72 hours. Luckily this was my spare mobile and I am ready to wait till eternity till Airtel gets fed up and allows by porting request. But how many will? Is this Airtel’s way of getting back at customers who want to move away from them? If this is not cheating, then what is?

I am waiting for the day I can get rid of Airtel.