"George Wenzel" wrote in message

The problem here is that the store didn't install the wrong item - you
did. As far as they're concerned, they delivered the wrong item and the
problem should have been noticed when you signed for the delivery. It
wasn't, the item was installed, and you realized the problem _after_ the
installation.

You're the one who is refusing to take responsibility - you signed for
the sink, despite it being the wrong item.

You may be right, but it depends on the labeling. If the carton had big
letter stating it was UNDERMOUNT, I'd side with you. If the carton has a
simple code that was a digit off, it is easy to miss. As the OP said, it is
nearly identical and he did not notice the difference. Probably most of us
would not.
Ed