Seat Belt Locked Up

I have a 2008 Monaco Dynasty Motorhome..... the drivers seat has a seat belt that pulls out from a slit at the top left (sitting in the seat) corner of the back of the seat..... we have not used the coach for about 5 weeks (but this should not enter into the problem).... when I sat down in the seat and pulled the seat belt across my body to snap it into the retainer part to secure the seat belt, it just kept on coming out until reached the end (I guess the end) of the seat belt itself. Normally it is spring loaded so when you get out of the seat, it rolls back up into the seat..... now it is just laying there and it will not roll back into the seat.... there is no spring action.

My question is: has this happened to anyone else and how did you solve the problem?

Thanks.... I appreciate any help you can give me on this problem.