Bad customer service from Kulula.com

Awful customer service from Kulula.com. I selected flights online and tried to pay with the instant internet transfer option, which wasn't operational. Returning to the booking page I tried to pay via credit card, which was rejected as it was a 'duplicate booking'. 4 days later, I am still waiting for assistance to allow me to book and pay - have held on for the call centre for hours, sent a query from the website contact form, and numerous messages begging for help on the Kulula Facebook page. The responses are along the lines of 'someone will get back to you'. I've just booked the flights with another airline, a 5 minute exercise, and will think twice before using Kulula again.