The client area keeps records of which domains have existed on your account. I checked these records, and I can see the domain paperx.is-great.net was hosted on your account. The domain paperx.great-site.net never was.
If you remember it differently, then you must be misremembering. I’m not judging, my memory gets fuzzy too, and the domains are very similar. But I have proof that what I’m saying is right. No memory or guesswork involved.
Because the domain you think you had is not the domain you actually had. See point above.
The domain is in use by someone else. And has been for a long line. You never had the domain, this other person always has.