Booking.com took my money

On the 26th of January 2024 I booked flights on Booking.com When I submit my payment, I received a message informing that the total is now almost R8000 more than the original price. I had a option to accept and continue or to go back to flights. I chose to go back to flights. The price was still R8000 more, so I decided not to book through Booking.com Nevertheless, Booking.com took the money from my Amex card. I phoned them immediately, but the lady said there is nothing she can do for me, I should just wait 2-5 working days for the refund. I received an email that the refund will be in my account within 2-5 working days. On Monday, 5th of February I phoned Amex which confirmed the refund still has not been made. I phoned Booking.com. The agent said that the amount I am giving him for the refund does not corelates to the amount on the system and that he cannot help me. He suggested that I send an email, but he could not give me any address where I should send this email to. I then logged in to my booking.com account and sent an email via that platform. In response I received an auto reply indicating that I can accept a call from an agent within 48 hours or sooner. It is now longer than 48 hours, still no response or phone call or refund or reply. How can Booking.com take the money out of my account for the 2 expensive flight tickets after I selected not to continue with the booking, then commit that it will be refunded with 2-5 days. Today it is day 13, still nothing from Booking.com. They took my money without my agreement and now they just keep it and make no refund or do not even reach out to me to explain what the situation is. For such a big company this is unacceptable, and I will not make use of them ever again. They are useless and *******!