Untrue, there seems to be no limit on the restorations you can have, as I've restored characters about 10 times on one of my accounts, however item restorations are different as the GM who did that said I only get 1.
they can stop restoring your characters, but normally they wont do that.
there was a topic in the official german gamemaster support forums of a player who didnt get his character again after around 20 recoverys.