Indian Bank — indian bank denying refund

Address:

Pune, Maharashtra, 411030

I had ordered a bag from amazon on 6th april but later cancelled the order. Amazon said they have initiated the refund on 8th april itself and bank has provided them with "Refund Reference id" which is the proof from their side that the refund has processed.
However, I still haven't received the refund. Amazon provided me with a refund reference id 75503729099028528209456. but Indian Bank denies this number saying that it is of no use to them and they need a transaction id. I contacted amazon and asked for transaction id but they say that they have got only "refund reference number" with them and no such transaction id.

I contacted customer care of amazon and Indain bank several times but they are just hitting me back and forth; amazon asks for contacting bank and bank asks for contacting amazon.