Ubereats refund process is a ****

I am beyond appalled by their service. I ordered 3 items from KFc using my Uber app and i only received 2 of the items ordered and missed 1 item which waa worth R50, 90. I immediately logged it on the app and they refunded R15 instead of the R50.90 which was the missing items worth. I've been trying to get help from them but no luck till today