HORRIBLE AFTER SALES SERVICE

We bought a heater at Stingray via Takealot, it lasted for about a week, then it started to malfunction. I've sent an email, as advised by one of their customer service consultants, my email was not acknowledged, I've called several times, every time I am told that I will receive an email on that particular day and a technician will come and collect the unit. To date, I haven't received any email and I haven't received a call, the unit has not been collected. I call every single day. I honestly don't know what to do.