IDEA postpaid connection
Wrong bill generated every month and outgoing calls resricted because of wrong bill

I am using IDEA postpaid connection. The bill generated in September includes the cost for the calls that are free according to my plan. The bill amount is around SIX times the bill i usually get. Then these Idea people disconnected my services. They are threatening me to pay the bill otherwise my number will be disconnected. They have already blocked my outgoing calls. Why should I pay SIX times of my usage and that too because of their mistake? My Mobile number is 9540968666. I am getting this kind of problem every month and going around talking to IDEA people day & night but still there is no result.