Sorry (again
) for not completely reading the post.
I would have expected a plant in better condition than the one you received and you are perfectly reasonable to request another plant. They may also want you to return this one and that is also a reasonable request.
I will say however in my experience that it is not unusual for catts to arrive with a bunch of crummy roots.
My standards are fairly high and I am continually dumbfounded that a plant can grow nicely with mostly crap underneath.
Catts are amazingly resilient and given a root trim, fresh potting mix, and some drying out, they usually and quite happily throw out some nice pretty green roots.
When it happens, you will shake your head in disbelief!