Airtel — prepaid balance 70 rs deducted for mobistore activation without my knowledge

Address:

560075

I got a sms in the morning from at-airinf telling 70 rs deducted from my balance:

[ thanks for choosing mobistore on your airtel mobile. You have been charged rs 70.0 for 7 days. A/c balance rs... At 00:35. To deactivate, call or sms stop to 155223]

I did not activate any kind of service nor i did subscribe to any service. Please overlook the issue and refund my money rs 70.0 back to my account and refrain from doing such illegal activity in future.