Canara Bank — Refund not received from the bank

I returned an item from Amazon on 23rd June 2020.They are confirming that they sent refund amount to my canara bank account on 2nd July but still now I didn't receive any amount.am really confused whether the problem is with Amazon or Canara bank.when I ask Amazon customer service they have given me the reference number for refund which is blaming the bank and [protected] similarly when asked to Canara bank customer care they are blaming amazon .