Reliance Communications — Activating Services without my consent

Dear Sir,

I am using Reliance India Mobile connection since last 4 years. I have never activated any value added services ever like Hello Tune, Caller Tune, Jokes, Bollywood masala or anything else. But they have activated such services several times without my consent. Whenever I ask them about deducting the amount, they simply say that ,from our records we can say that this service has been activated by you, that's why this deduction has happened.
You tell me what I can do in such situations?

Regards,

Sujeeb Singh.