Vistara — Money not refunded for tickets not issued

I had made a booking in Vistara airlines for travel date 22nd Feb.
however while making the booking there was an error in the network/system and money got deducted from my ICICI bank account.

several calls were made to customer care on this issue and have given two service request no. there was no acknowledgement of the issue on mail or in writing. have been chasing them to update either on non receipt on of the payment or refund the amount of INR 6432

SR# TCT[protected]

mail to the id [protected]@airvistara.com was sent on 14th March with a reminder on the same after a week. There is no response on the same.