Sell clothes that come apart at the seams and won't refund

So not impressed, won't buy clothes from Makro again. Bought 2 pairs of pants, wore them once, washed them in the washing machine and 1 has a large hole where the seam has come apart, the other is starting to come apart at the same place. Take them back to Makro because it's obviously a manufacturing fault but I can't return them because I'm at fault for not wearing them straight away after buying them so it's been a month. Tried to explain that I didn't know that they were going to fall apart so didn't know I was on the clock. Oh and apparently my other fault is I used a front loader washing machine so I'm the one that 'broke' them. Makro should put a large sign up by their clothes saying only use top loader washing machines. Useless, irritating idiots.