bad quality product

2 months back i was convinced into purchasing a pair of levis denim jeans worth R800 at the Tygervalley mall in Cape Town, i was told the brand produces strong quality denims which apparently last a life time, its not even 4 months now already its damaged and not sure how. it appears to be torn at the back but i took it to a tailor hoping the damage would not be visible but still is, and it appears to damaged at the front but also not sure how, im not sure how your jeans will 'last a lifetime' if it cant even last 6 months! i need the product to be replaced immediately as i bought is thinking i could trust the brand, if it cannot be replaced then i want my money back so can purchase a really trusted brand. don't know what i did with your slip though...