Tata Docomo — raise in call rate from 1 paisa 1 sec to 20 paise per call

Address:

Kolkata, West Bengal, 700090

Dear sir/mam

I am from kolkata i have been using tata docomo for more than 8 year. The call rates are 1 paisa 1 sec. But few day back suddenly they have raise 20 paisa per call. Without my knowledge. I had send sms to stop this but nothing happen. I called customer care but said that its a offer which ever customer of docomo has to bear whether they want it or not. Please resolve this matter asap.