Felt and still feeling De*****ed!

I have and I am still an FNB client, together with my business, but, however, the way they treated me during a recent transaction still leaves a lot of room for them to improve. In March 2025 I made a purchase (as I always do) of R1,117.00 on TEMU around midnight. TEMU messaged me and indicated that my payment has not reflected, and there was a button inviting me to repay. I did that, meaning I paid for the purchase twice, same amount. I only discovered this the following day. I followed up with both TEMU (what a struggle!) and have all communications, trying to call my funds, to no avail. I also followed up with FNB bank, filled forms, FNB contacted Nedbank (TEMU's local bank), to no avail. I emailed FNB bank as my bankers but still hit a brickwall. The response they gave me was "According to the attached response that was sent to you, the recipient's bank could not obtain permission from their client for the reversal to take place, the recipient's bank is not able to lawfully share the recipient's details with FNB." To date I feel one party has my funds and just do not want to refund my money, and everytime I think of this, I get a sour test taste in my month and wonder if this is the right way of doing doing business in this day and age.