Makro Centurion - really bad repair services

I bought a Cadac heater on the 4th of May at Makro Centurion and it started malfunctioning on the 3rd week. I took it back to the store just before the 4th of June and I was told that it will not be replaced immediately and I would have to book it in for repairs which would take up to 6 weeks.

The only thing that was malfunctioning was the nob and the heater couldn't stay on for long - I don't understand how fixing it could take 6 weeks - during winter when it is most needed. The cashier who was helping me didn't seem to listen or care that I need the heater soon. The heater broke down less than a month after purchase - was I not supposed to get a new one - replacement immediately?

It has been 2 weeks now and I haven't heard anything from the store. I have been calling the store all morning with no response.