BOLT refuses to refund an overcharge

Sunday 21 Feb: The first Bolt Taxi driver that arrived demanded that I pay him upfront in cash for the trip, even though Bolt had already reserved the amount on my credit card. When I refused he became very agitated and left. Had to order another Bolt Taxi. I was overcharged for the trip by R60 due to a ‘GPS error’ according to Bolt. Okay - mistakes can be made...yet even though they have acknowledged the mistake, the company is refusing to refund the overcharge...instead wanting to give me a voucher which will require extended spend with them. No Bolt SA - this is *********. This review isn’t written on a whim either, I have tried resolving the issue with customer service representative SIYABONGA with absolutely no success