It is a common practice amongst these companies to add value added services like caller tunes without the customer’s permission which is totally illegal.Since most of the customers do not know how the billing is happening and do not know how to turn it off,these companies make millions of dollars in illegal profits from such customers.Airtel,Reliance and other major telecom companies in India follow this practice widely and openly.Nobody is going to complain about 50c/month being charged wrongly by the telecom provider.However 50c multiplied by a 100 million customers is neat $50 million in profits for these companies.This overbilling of customers even extends to broadband customers as I recently found out .After a nightmarish experience with Tata Indicom whose pathetic customer service forced me to change to Airtel,I found a blatant case of overcharging of money in my very first bill.