Airtel — automatic 3g loan

Address:

Nagpur, Maharashtra, 440001

I just took 1 3g loan of ₹14 because i was traveling and i needed internet. Then on 25th, it deducted another ₹14. And i didn't even ask for any more 3g loans. I found nothing at their support service. I sent them email, but they haven't satisfactorily answered my query.
Then today, they again deduct ₹14. I found no option to deactivate this auto 3g loan service. And now i have only ₹7 in my main balance.
I can't loose my money.
I just want to deactivate that 3g loan service.