Double charged me

I'm so disappointed in Bolt services. The driver ****** me day light without me being aware.Mistakenly I had given the driver R50 cash not being aware that I was already paying with my visa card,which means that I ended up paying R100 for a R50 trip. Kindly issue me with my R50 refund please. I honestly cannot pay R100 for a R50 trip because surely the driver could tell that I was already paying with my visa card,he could have just made me alert and not taken the R50 cash which I had given to him.