balance deduction

i recharge my account with 60rs.after some day ,there deduct the amount from my balance (account).when i call 198 .there simple replay that your subscrib that service.if it happen one time i thing it my mistake but every month aircel network deduct the balance.
on 6-aug-2014,my mobile has low battery charge and it go to switch off .at evening ,i put my mobile to charge a battery and go to the bathroom .when i come and see the message that ,(thank for subscribing to dial n-chat at rs 35.00 for 30 days validity.you will be renewed after 30day.To unsubscribe sms stop to 155223).i was shock .and dail 198 .but there simple replay that your subscribe that.this type incident happen every month