Defy Microwave not working

bought my defy microwave at Makro 2 September, it only work for that day..the following day it wouldn't heat up food it would just run with the light on..but because I live far from home I waited to get back home in Pretoria to take it back to Makro, I was told my 7days had already passed for a refund and that it will be taken to wherever they fix the defy problems, on I got it back on Wednesday last week and it worked fine, today is Monday,guess what?🤷 the same problem AGAIN!!!