Levi jean defective

I bought 2 levi jeans 8 months ago, they have faded so badly and is totally worn. I contacted levi and they said the store should sort it out and the stores just says it's not their problem. I bought a Merrien Hall jean 2 years ago which I only paid R200 for and it still looks like a proper jean after two years. Unfortunately I can't say the same for the levi it's totally not nice that a brands quality is so bad and then no one wants to take responsibility for it.