double money deducted by airtel

Location/place: Kanpur(UP East)

Name of company/service: Airtel

I recharged my mobile with rs 50 top up followed by an sms pack of rs 36.however the airtel renewed my previously recharged sms pack and deducted money from by mobile balance.no money refund was made when i stopped the renewed pack.airtel should have a track of recharges and should not recharge two times.Kindly refund my money asap.my number is 8853918738.