Shocked at price and what you get

I bought a pair of the highly expensive jeans and about 6 weeks later I found that underneath (crotch area) it has started tearing. I went back to them and they said no returns after 30 days. Then I bought another pair hoping it was just an unlucky pair and in just over 2 weeks the same thing happened and this time they said that after 10 days it's no money back but they can replace them. I asked why this happened and they told me sometimes it happens at the factory that the needles don't knit tight enough. I'm sorry but what??? I'm paying over R2000 for these pants and this is what happens ??? I'm highly upset.