Never received the booked vehicle

I booked and paid for a vehicle for my son from Cape Town International airport for today 20/02/2018. As I have paid for his flight return tickets from Port Elizabeth I booked a vehicle from rentalcars.com. They refused to give him his car or even a refund. During his flight he forgot his credit card hence their refusing the car. you can imagine my agony as a parent for my son's sake as they can only say sorry and that they can refund if he uses them again. I have tried phoning them to sort out something. What ever happened going the extra mile. My money was good enough to *****. Never in my life will I ever use these people again. It's not just the money but the fact is that he is stranded at the airport. I wouldn't even rate an one. Maybe zero