Univa - Refund not being paid

I sent back a univa oven on 07 Oct 23 and it was collected on 10 Oct 23, the collection is marked return concluded on my profile,but I don't get my refund, I phoned 3 times and everytime I am being told that they will follow up,nobody gets back to me. I provided all information requested from me,how long do I have to wait in order to receive my refund or any feedback? Absolutely disappointed in all parties handling this return