Is the seat belt stuck where it latches together, or is it stuck and will not stretch across far enough to latch? If it is stuck where it latches, then this could be coins that lodged into the receiving end and causing it to stick. These can be difficult to get out and one method is to depress the button while prying with a thin screw driver. (Be careful not to bend the screwdriver though) IF it still does not want to loosen up, try prying on one side and then switch to the opposite side(to walk it out) but before doing this, add a small amount of penetrating fluid to the latch and wait about 5-10 minutes before prying again. If it is stuck so the belt will not release from the wall or floor of the vehicle you will have to remove the plastic covering or molding to get to the ratchet mechanism. The ratchet mechanism may nee oiled and worked to get it moving once again. There is a lever in the ratching mechanism that would be the cause of the hang up.