Jiomart - No refund issued

I have ordered Groceries on Jiomart app. The amount was paid via CRED UPI. The amount was successfully debited from my account but the order is not confirmed. I called Jiomart customer support and they told that due to technical issue, the order is not confirmed, any amount deducted from your account will be refunded within * days. But I didn't get my refund after * days, so I contact them via email (including CS head) with my bank statement proof. They closed the issue after * days stating that the issue has been resolved. But I didn't get refund. I contacted them via call as well as email again and they closed the issue again stating that the issue has been resolved. How do I get my money from these fraudsters?