Idea bill plan changed without confirmation

Location/place: Pune

Name of company/service: Idea Cellular

I am a Idea mobile postpaid customer .My ph no is : 8308819155.My bill plan was changed by company without confirming me.They are saying to pay for the new plan that is much costlier to me.Now deactivated my idea no. and waiting for settlement.But there is no response from idea care.My registered complaint no. is 156801922. My current no is 9899464033.Please help me to resolve the issue.
Regards
Pankaj Mahawar
9899464033