Uber cash missing

On Wednesday evening I took a Uber ride home. My trip total was R61 I paid R100 to the driver he didn't have change so I asked him to add it on to my Uber wallet . I got out of the car when I had seen the R39 in my wallet . Yesterday morning when I tried requesting the amount was not reflected in my wallet . I wrote to support and asked them to rectify the mistake ,I was assured that it would reflect on my next trip . I have taken 2 more trips and I still have not been received my money . I don't know what to do at this point