Webafrica zero support and incorrect billing

I have moved house recently. The process online on their website went smooth. They said I get a free upgrade for 3months from 20mb to 200mb line. Now for the past few months I have been billed my normal rate of R700 to R800 and an additional R1539. I can't get hold of them on the phone and when i eventually get connected on their whatsapp support the person doesnt respond or i get disconnected. This is a nightmare getting hold of any support.