[Resolved]  Matrix Cellular Services — Incorrect Billing

I took a Matrix connection in october '09 for a month while I was travelling in Europe. The customer service agent came to my office and promptly did all the paper work and delivere the SIM. On my return from UK I had called up the customer service to have the sim card collected but I was told that I can retain it without a charge if I am travelling again to Europe. After receiving a new Bill on 31st December for Rs. 1538.8, I called up the customer service and I was told that the bill has been wrongly raised and it will be reversed within 40 days.
To my utter surprise I have received another bill of Rs. 5454.76 and my card has been charged for the same.
I have been following up with the company but with no results.