[Defeat]

Well, i thought, as long as the item is shipped by amazon it´ll be allright.
Seems they scanned the code on this item and it was not in the database. Or how would they otherwise know it?

No one is going to know exactly.
You could have asked them. Calling probably would've netted better results as well.

You sent the wrong item in - they told you they didn't stock that item - sending it back to you - noted it to your account and told you to try sending it back again? I'm I following correctly?

I agree. I find with the wrong item claim, it's best to call before you even let them process the item. That way you avoid an issue like this.