Travelstart NIGHTMARE

I have been trying to reach @Travelstart for 2 weeks now and am incredibly frustrated with their absolutely horrible customer service. I have a credit voucher for an overseas flight I booked via Travelstart that was cancelled during the height of Covid. Now I want to use it to book basically the same flight to leave in April. I have filled out and sent through their website contact form five times, with no reply, and tried to contact them on WhatsApp at least six times. Only once did a a real person reply to me on what's app, and she left me hanging on the line for over an hour while she "checked to see what to do". Then she just never came back to me, and no one ever has since then. There seems to be no way to speak to a human being to help you. If I don't get hold of them soon I will be out of a R15, 000 ticket. Can't go directly to airline unless I cancel with Travelstart first. NIGHTMARE!