Order not delivered

Good day. I am extremely disappointed in the Uber Eats service. I ordered food for my grandmother yesterday. When I checked it said the food had been delivered however my grandmother called to tell me she did not receive the food. I queried it on the app and was told the driver tried to contact me and waited the correct time before leaving. The driver did not hoot and did not try contact me and are refusing to refund me. I had to place an order with Mr delivery and pay for a 2nd time. This is absolutely ridiculous and not the first I have heard of drivers doing this to customers