I am using airtel prepaid (p.no 9994017269) for last 4-5 years under various schemes.Yesterday I was charged 1.00 rs for sending SMS. When inquired from customer service i was informed that my plan has been changed & a new tariff of 1.00Rswill be charged for the first sms i send & after that 100 sms will be free.I want to know why should i use airtel when my tariff is changed without my consultation or information & what advantage it has got over recently launched TATA DOCOMO, which is charging 1paisa for 1 sec.why shouldn't i switch.