Apple Cash Refund Not Received

I made an online purchase for a restaurant using Apple Pay Cash. The Apple Pay Cash was not pulled from my bank account, but rather was in my Apple wallet after someone had sent it to me through Apple Pay. I requested a refund from the restaurant due to an order issue, and they assured me that the refund would be processed starting on 02/11/24 and I would have the funds within 7-9 business days. It has now been over a month and I have not received the funds. I contacted the restaurant who insisted the refund was sent, but after I requested a further look into it since the funds were not received, they are no longer responding. I contacted Apple as well who says they have no record of the refund and cannot help me any further. I am at a loss as neither party is helping. Any ideas???