Don't buy from webuycars.co.za

I bought a Volvo XC60 from webuycars. The car went for a full diagnostic and service on their recommendation before I collected the vehicle the cost of which was added to the purchase price. 3 days later the transmission overheated and left me by the side of the road. I towed the car back to the diagnostic centre where it went for a service without any assistance from webuycars. It has been 4 days now and I'm still waiting to hear from webuycars on what the next steps are. I have lodged two complaints on their website and phoned them with no success.