AMC Classic Cookware Rip-off

Ten years ago my wife bought a full AMC Classic Cookware and stored it. When our daughter got married six years ago, she gave it to her as a present. Subsequently one of pot's bottom came loose. Took it to the agent in Lansdowne Western Cape. They said the pot overheated even though the inside was not burnt. She must pay 50% of the replacement cost (about R2500): What about the life-long warrantee? Why did it not happen to the other pots? It is obviously a flaw in the manufacturing process!!! Phoned their customer service and they just refused to listen and was very unapologetic. In fact, the lady (whose name I have) was actually very rude. These pots are so expensive, one would not expect this type of thing to happen and such poor client service. This does not even happen to cheaper pots. Is there any consumer watchdog that I can report this to and get some assistance?