Taxify (bolt) regarding money

I took a taxify (bolt) home and the guy charged me R166 cash. When I got inside the money was also taken from my account, but the amount was R151. I contacted taxify (bolt) to try and sort out the matter but they just said that the driver said he did not take any money from me and haven't contacted me back since. This is so unacceptable. Taxify (botl) are literally robbing people. I am completely upset and to make things worse, they have stopped replying to my messages about the matter.