Idea post paid bill issue for last six months

Hi I am Binoj,

I have idea postpaid connection 9911201569 with a rental plan WIPRO_99 (corporate connection). Main features of my connections are:
• All CUG calls are free,
• Free 300 Local/STD minutes excluding CUG calls and
• Free 300 SMS
• Rs.98 GPRS pack is also activated.

Iam getting regular faulty bill for last 6 month

Issues on my bill
• My CUG calls are included in the local calls list and it getting charged
• The GPRS usage is also got charged
• The CUG consuming the free local calls and the local calls are getting charged
I have complained the same each and every month through by calling customer care and nodal officer and through mailing and got waivers. they disconnected the connection several times and persuaded to pay in order to get my incoming and outgoing back. Now i have overpaid approx Rs.800. after getting the 6th faulty bill i decided to surrender my connection and went Idea head office Noida. But they disappointed me by saying that If you want to disconnect you need to pay the total faulty bill. ie approx Rs.1400. If I calculate my bills and payment in proper manner, idea has to pay my money back. Now I am in the middle of the sea, don't know what to do

Please help me to get out of this.