Airtel — balance disappearance without using service

RS 100.00 from My Airtel Prepaid Balance has just disappeared while my phone was not using. I had kept my sim in a basic phone just to receive any incoming sms while I was in Qatar. My phone has no GPRS / internet facility.

Incoming facility call/sms is blocked due to some unknown reason, and when I tried to rise a complaint through email, they were asking to authenticate the email address through OTP which I never received in my blocked mobile.

I have contacted them through face book, and an executive told me that the balance was deducted due for data usage.When I provided him with my phone's model name and IMEI number, he stopped replying my im's.

I need my credits back and I will port from Airtel as soon as my issue is resolved