Reliance Fresh — Refund required for an uncalled transaction

Address:

Hyderabad, Andhra Pradesh

I made a purchase in one of the reliance fresh outlets . However, just at the nick of time there was a server issue and the swipe transactions were getting cancelled. After 20 mins the server was up and the transaction went through. However, I was also charged for the swipe that was processed as soon as the server issues started. So I was charged 2 times instead which should have been once. I was told that the charge will be reversed back to the account which has not happened still.

Want to know how long does it take for the charges to get reversed.