Megan,

First check the fuses. Did both belts stop working at the same time?

Second, manually crank the belts into the rearward, locked position (the manual tells you how to do this).

Third, pray that you don't need new seatbelt motor assemblys. They run about $400 each. If this is the case I would either find a good used set, or just operate the buckles manually using the emergency release button.

Dave