Indian Railways — Refund payment not received

Dear sir/madam,

We had cancelled the train tickets and not received the amount back.
The payment was done through credit card.

Till now regularly we are visited reservation counter (Secunderabad), they are not giving proper answer about this.
They are saying you will receive and we don't have details of this that's it.

Pnr numbers[protected],[protected]

Please do the needful.