Union Bank Of India — Not refunding money for failed payment

Address:

UNION BANK OF INDIA,TIRUVANNAMALAI BRANCH

I ordered redmi note 10 mobile phone on amazon app on 12th april at 9:08 am and i made the payment by using union bank netbanking. After that I recieved a sms from union bank of india to my registered mobile number like this, Transaction for INR|13999.0 to CITRUS PAYMENT SOLUTIONS has been completed successfully with reference id[protected]. But in amazon app i recieved notification like this, your payment for this order could not be completed, please retry the payment. If money has been deducted in your card/bank account, it would be refunded in 2-4 business days.payment failed but money debited from my account.till now not refunded the money, more than 7 days went. I asked amazon customer support also, they said money did not received from my end please you will ask to your bank. Again i asked union bank of india custome care, they said, i filed your complaint and the money will be refunded soon maximum 3rd may. But i need a clarification, when will refund the money who side was the problem, bank or citrus payment solution or amazon app.