Refund stuck for 2 months - Merchant says refunded, Slice says they never received it. What should I do?

Hi everyone,
I’m posting here because I’m out of options and hoping someone from Slice or the community can help.
In April, I made a purchase of USD 17.90 using my Slice card. The order was cancelled, and the merchant (Witrigs) processed the refund.
According to the merchant:
Refund was successfully completed on May 15.
They’ve shared their backend screenshot confirming the refund.
They’ve also shared the Payment Id and said they can provide any additional information if required.
However, it’s now been almost 2 months, and I still haven’t received the refund.
I’ve contacted Slice support multiple times, but they keep telling me:
“According to our records, the transaction has not yet been received… the money has not been credited to us.”
So I’m stuck between the merchant and Slice:
✅ Merchant says the refund has been processed successfully.
❌ Slice says they haven’t received anything.
Has anyone experienced this before?
Can Slice trace this refund using the Payment ID or should they be asking the merchant for an ARN (Acquirer Reference Number)? If this needs to be escalated, what’s the best way to do it?
I’d really appreciate any help from the Slice team or anyone who’s dealt with a similar issue.
Thanks!