Just called. Canon says i need a new focusing screen, and they will cover it under warranty, since my camera is only less than 2 months old.
I can either send it in for servicing or purchase a new focusing screen and do it myself.
They said thats what they do to all problems concerning the focusing screen, replace it, dust or not.
Even if you send it in for sensor cleaning, if you say something about the focusing screen, theyll put a new one on.