Airtel — undue deduction of money from balance

Airtel has self activated whatsmob service on 3/02/2018 and deducted r/s 75 from my balance without my consent.
On seeing the message i got it deactivated but r/s 75 were not returned.
It is unethical practice and need to be stopped.
Airtel to return the money and penalty for unethical deduction and pain to customer.
Avadh
Phone [protected]
Email [protected]@gmail.com