Faulty equipment on Makro Carnival shelfs

I really needed to buy an Inverter for my dad this past Sunday, the X2 Mecer Inverters on display had both the word "Faulty" written on it. I mean how can you have things on the shelfs that are faulty...? I called someone for assistance, where he disappeared with the box not saying a word and then eventually coming back saying yes it IS faulty. What if one bough that without seeing the word faulty on it.

Not professional at all!