Are you sure the blade is turning? If its not, there is a hole in the bottom you can fit an allen wrench into to turn the motor and break it free again.

I would try getting the blades to start moving. I used to have this issue all of the time in my college housing. Fortunately, we has easy access to plumbing services and were able to get the handymen on the scene quickly to get it taken care of. If there's anything that I learned during that time it is that there are some things that should not get put down the drain. http://absolutelyclearsewersandplumbing.net/Services