Idea — Wrong billing

Address:

Gurgaon, Haryana

I am using idea postpaid connection, my number is [protected], my bill plan is 299 i plan, and a gprs plan of around 4 packs for GPRS 3G, my bill genetaion date is 1 to month end i have activated plan on 27th may with in 3 days usage i got big bill . i have aroung 400 mb but i got 740 rs only for GPRs usage .and after this they generated bill of Rs 1224, in one month that is of may 2014. this is disgusting, and one more issue is i have changed addres so i given all documents they verified and changed my address wrongly. if i ask them, they are telling once again i need to give all documents thaen only they change..its worst service.
i need to change as early as possible to other.all please carefull.