Charged for service not rendered

On the 13 October 2019, I used the Pick 'n Pay bus booking system (Flight site), it was not my first time to use it. I booked the bus, chose the credit card payment method, entered my card details and confirmed payment. The system hanged and cancelled my process before it could return the success results and sent me back to the home page. I tried the process the second time and it did the same thing and I decided to leave and go book the bus at the store. I noticed the following day that the system had charged me for the 2 times I had tried to book and fail but no booking confirmation or tickets were sent to me. I then went to Pick 'n Pay to enquirer about this and they reversed the money back into my account or so I thought. I have just noticed now that the money was deducted again from my account by Pick 'n Pay. I want my money, I cannot pay for a service I never received.