Airtel Prepaid — debit of money automatically from account

dear manager.

i am manish kumar, user of prepaid connection with your company( airtel ).my cell number is [protected], i have a message from number 4774 intimating that my missed calls alert service activated without my subscription or any request to airtel. and
automatically 15 rupees deducted from my account from balance rs 2 to negative balance rs 13.

its not the case of just RS 15 .its fact that company is having lakhs of connection and missusiing their accounts with these types of obligations.

i have already complained to customer care but no any positive response acuted.

i request you to please reimburrse my dues back...

early response will be appriciated .