Uber *****s

When I finished my trip I was paying cash, and I got out of the uber paid the guy R100 and he left.. after a few hours I wanted to see if he put the change on my account like I asked, and all of a sudden it said I'm owing R50 for a R70 trip that I paid R100 for. And I'm an Uber one member and I'm getting ****** like this.. utterly disappointed