Uber driver doesnt want to refund my money.

Hi. Last week I had a ride on Uber from Midrand to Bryanston on the 03/04.2018. I would normally pay between R155 and R180. That day a driver of this car DK 25 BK GP charged me R308 and when I tried to get clarity he said to me It was the Uber system. I had only R200 cash and I said I will transfer the rest and he agreed. I gave him that R200. Just when i was about to do the eWallet for him. I got an email from Uber saying that they have corrected my invoice an I need to pay R155. I called the driver and he said he will refund my money. till today ha has not refunded me and he is saying that he did not get my numbers sent on whatapp. He is very rude to me. He needs to refund me an amount of R45.