Refund for unused ticket

In March  I purchased  two tickets to be used on Caribbean Airline for travel to Jamaica in July. Due the Covid 19 outbreak that did not happen. I have since received a refund for one ticket payable to my Discover card. I have yet to get the 2nd refund which should have been sent back to my debit card at Ridgewood Bank. The booking number 67722958 for Flight #10. (other booking number 67296401). I contacted the billing department and was instructed to check with my bank. I did, no record of a refund was found. Could you please look into this matter for me. Please note that the email address used to purchase the ticket is different from the one I am using now .If you need additional information please let me know .Thank you for your cooperation .Looking forward to to hearing from you soon