Airtel Prepaid — illegal way to subscribe people

Address:

Jhunjhunu, Rajasthan

My mobile no. is [protected]. I am using airtel prepaid connection. I do not use any value added service/caller tune/dialer tune etc. But airtel automatically subscribes me to any of its services and deducts balance from my account. When I complain to customer care, they disable my services but my balance is not refunded. Every month I lose a good amount of money because of this.
I want to get my money back. I also want to know what should be done so that Airtel does not repeat this with me.