Uber service is terrible

On 26 February uber driver by the name of Phumalni Registration number ND 581283 dropped off my son in Chartwell drive, Umhlanga and drove off with his new IPhone. I reported the matter to Uber and they requested rider to raise the query. He did but they never ever responded to him regarding his query. all the details of driver were on the phone and fortunately we retrieved the trip via email that is sent out. Uber said they couldnt pick up the trip as though it never happened. I am shocked as to hot they cannot pick up a trip which was taken. A few days later we tracked phone in Albert Park at some foreigners shop where it had apparently been sold. Uber did not take responsibility for this and after reported support messages we sent we still were not able to trace the phone. The driver is apparently still working and we have lost all hope in Uber. Unfortunately i feel like we will never use their service, no matter how convenient. How can a company say they cannot pick up the ride? Very disappointed