No refund of wrong deduction

Location/place: Mumbai

Name of company/service: Vodafone India

There was a wrong deduction of around Rs. 94 on my prepaid mobile no. 9819136523.
but it was not refunded to me. in the mean time i migrated to postpaid and they promised to adjust the amount in bill which was not done.
its been over a month now and every time they just give me a new complaint no and assurance that this time it will be done.

the latest complaint no. is 1281369196

please suggest what to do.

Regards,
Harsh Bafna