Airtel
Deducting extra amount for chargeable websites

I have recently switched my mobile number (8055790757) to Airtel and subscribed to a 3g data pack (1GB/month free usage). I found that some amount is getting deducted from the main balance for internet browsing though 3g free usage is still remaining.

I called up the customer care professional. They say that there are some chargeable websites for which balance will be deducted from my main account balance.

I neither found the list of such chargeable websites on Airtel's website nor received any alert messages while browsing them on my mobile.

I switched to Airtel though it's is well-known for such kind of frauds, Did I make a mistake?

Thanks,

Sai