Online booking and bad Customer Service

I'm extremely disappointed with kulula's service. I have tried 8 times to book a flight and each time get to the payment page and they reject the payment. I have tried on different computers, different forms of payment (different credit cards and SID) and each time the payment gets rejected, and the price for the flight goes up. I phoned customer service and was told that I must try again and its not their problem that the price keeps going up. They were beyond unhelpful and it is ridiculous!