Airtel — Unnecessary balance detection

Address:

Chennai, Tamil Nadu

Hi,
I would like to raise a complaint against Airtel mobile Service Provider. I have been detected Rs.36 from my balance without any intimation saying this is for message booster. Booster pack is something is should wish to add to my mobile number but here its airtel forced me to take it up by detected my talk time balance. Please let me know what should i do to proceed further for filing a complaint.

Note : I have called up customer care for this but they said they cant help for it.

Thanks,
Thilak