Airtel — high postpaid bill

Airtel is now looting their postpaid customers by sending high bills.. I am on 499 unlimited plan for a month, where as they are giving unlimited paln for 399 for three months to their prepaid customers.. Don't understand this policy of airtel, 1st they push u to go for postpaid connection saying it has more benefits n later on they send high monthly bills... My pan is 499 unlimited on which they have send a bill of 1447.. When i call their customer service, their executive rashmi who don't any manner to talk to the customer was not ready to listen to me n showing a lot of attitude as if she is a owner of airtel.. She told me there rs. 720 extra charges of roaming.. My question is i[censored] can provide everything including roaming free to prepaid customers for 3 months @399, then why not to postpaid customers @499 per month... Rashmi told me very rudely that all charges are genuine n u have to pay the same... Also when i told her abput the prepaid plan 1st she denied saying aapko pata hai woh recently start hua 2nd feb, that is such a big lie she told.. My wife is using airtel prepaid connection n i am doing 399 recharge for her from last 9 to 10 months... When i told about this she immediately took a turn by saying she was talking about postpaid n not prepaid.. Earlier also this has happened few back when i got a bill of around 740.. That also i complained n told them that i want to port to vodafone.. From next month onwards my bill was reduce.. But this time they cross their limit by sending a bill which three time more.. This time i will definitely switch to vodafone n will not use airtel service anymore.. Also will make my wife switch to vodafone as well..