[Resolved]  Airtel — Change of Scheme Automatically

actually i have a prepaid sim card (friends pack) of Airtel company and that gives facilities of calling 5 friends who are using airtel sim cards @0.15p/ min. also SMS charges to any other networks 0.15p/sms..and other networks calling rate Re.1.00/min..
My validity was getting over so i called Customer care for helping me for what amount should i recharge with so that i get 1year validity and i had also specified that my scheme should not change.I called Airtel customer care 4 times to confirm (because all executives give differents ans. So its better to check again and again) and then trusting on them i recharged with Rs.256 with zero balance and i got 1year validity. And after that i saw that ma calling rates for 5 airtel friends changed to 0.30p/min and Sms charges 0.20/ sms..i called customer care and the response given by them did not satisf me.. they apologised me for their mistake and told me that now they cant do anything for me and i will have to continue with this scheme..but i want the same scheme which i was using..Its a mistake from their side and not my mistake..What should i do to get my same scheme back