Won't replace iPhone cable with lifetime warranty

At Century City IStore, Cape Town, they refused to replace my lifetime warranty cable which I had for less than a year claiming that they needed the boss's approval. Suddenly they were unable to reach the boss and I waited for nearly an hour. The weakness of apple cords is intrinsic to the product. I have bought many cables for my MacBook Air and iPhone. Thats why the I-Store recommended the lifetime warranty steel cable yet refuse to replace it. The spikes are dangerous and hurt one.