[Resolved]  Vodafone — Postpaid bill amount refund

My bill amount for November 2007 was Rs. 817.38. I had standing instructions set to pay the bill amount through my account. As I was discontinuing with the number, I put in a request to discontinue the standing instruction and paid the amount on November 30 2007 manually to avoid late fees. Later I noticed the amount was deducted from my account too for Rs 817.
When I informed customer care, they informed me that the excess payment would be refunded back with the deposit amount (Rs 500). After repeatedly following up on it, after six months I received my deposit amount of Rs 500 back (it should be done within 60 working days). Even after repeated complaints later, faxing them the statement reflecting double payment, showing the same at Vodafone store, still now I have not received the excess paid amount. They are literally parasites, squeezing out money from customers. I am planning to discontinue even the present number that I have which is a Vodafone connection. Please let me know, what could be done to teach these guys a lesson, and justice be done.