39 weeks - no response from Wits

My daughter has an international sponsor for her Masters degree which she is studying through Wits. In March last year she submitted her proof of payment from her bursar and logged the necessary ticket to have it allocated. Wits are harassing her for payment and charging interest but they have not responded to her ticket (which is still open) for 39 weeks! We can also not get hold of a single person to assist with this - the numbers are just never answered!