Driver tips himself

I was in a ride last night from Florida to Krugersdorp. When the driver ended the ride he did not stipulated how much it was. And I gave him the money my wife gave me earlier thinking he will provide me with change. But then he drove off. My wife immediately started calling the driver through the app cause the ride was R174 and I had given him R300. He immediately did not want to answer the phone. And kept on declining. He could not have been 500m from my house when we started phoning him and untill now he dies not answer. He has to return the money and the fact that he refused to answer the calls means that he knew what he just did. My name is Dewald Ernst my cell number is ***. And my email is ***. I did tell support and they said it will be sorted out immediately but that was early this morning. No help since