Taxify driver

I requested a trip on the 17.01.2020 the drivers name is sylvester.am a huge customer of taxify and am so disappointed with this particular driver behaviour.my trip was supposed to end at braamfischer and wen we arrived we couldn't end the trip and he suggested that he leaves and he will find network to end the trip mind due I had a promotion so my fee was supposed to be around 68-70 so as he left he ended my trip at vlakfontein and the trip charged me 100 ...and I ddnt check as well as I was struggling with network .he called 20minutes later saying my trip cost him 21 so we should pay the difference so I trusted him we paid him R50 cash and my trip was a card . tomorrow morning as I wake up I check my app i was charged R100 not R21 as he said I called him to bring back my money he said he would on the background before hanging up my call he says in Zulu (nangu ezongihlanyela ucabanga ngingadla imali yakhe.) So m being called crazy as well by a driver..am so disappointed and would not wish to meet such a driver it's so scary as i sometimes request trips for my kids. It's not about the money but the drivers misconduct.and i want my money even the one I was overcharged with cos my destination was not vlakfontein.