Either way, people need to remember what a donation really is.
It's a gift to the server, not a purchase.
To encourage donations servers usually reward their donators but this is up to the administration to decide.
There are no guarantees of anything when you donate and the administration is allowed to do anything with realms/chars/whatever.

Let's not forget that the whole premise of a private server is illegal, so you are never guaranteed anything.

TLDR: Let it go, just play.