prepaid account balance

Hi Amit,
I am facing a problem in my prepaid account balance. I had made a topup of Rs.150 in the month of June. Later after a month, that is in the month of July the balance I had was deducted. Immediately I called the customer care and enquired the reason, initially they said that topup is valid for a month, but then during the period of topup I was told talk time is valid till the expiry date of my recharge. Later they said their might be some technical problem in their system and would refund my amount by 3rd Aug.
I had logged the complaint on 30th July. I have been calling the customer care quite a lot of time and they still keep telling that I will get my amount refunded. I can list some people whom I spoke with
1> Pavan Shirsagar
2> Sandeep
3> Laxman
4> Sangeetha
All of them assured that i would get it refunded, but no effect.
If the customer care continue to work in this, it will definitely loose many customers. If my issue is not getting solved then surely I will be moving out of this and even insist my friends not to go for this.
I hope you can help out with this issue. Please do the needful.
Regards,
Soundarya