That's too bad. I've ordered it many times, including the locations at WDW, San Francisco, Santa Monica, and Lake Tahoe. and have never had anything that appeared the way you described. They definitely should not have served that to you.
As far as the pasta, I've had mac & cheese made with many different types of pasta other than macaroni, but I still consider it mac & cheese. Even the popular blue and orange box of mac & cheese doesn't use elbow macaroni, if that's what someone is expecting when they think of macaroni.