DRIVER COLLECTED CASH PAYMENT BUT REPORTED ME AS NON-PAYER!

I booked an Uber delivery today and chose the option to pay CASH. R81.00 was assigned. Uber driver was on time, took my R81,00 (on camera with a 2nd witness) and drove off. Later I received an email from Uber that I did not make payment yet. I tried to contact the driver on his. Cell nr 073... with his known reg nr as well, he has now blocke my nr. As per Uber App I still owe R81.00 which is FALSE. ALL attempts to report and get my name and payment cleared to no avail. What now??? Why would a driver COLLECT AND LEAVE upon a CASH booking without receiving his money? I am VERY VERY UPSET!!!!