1993 Mercury Topaz Safety Belt Problem

On my drivers side, the automatic lap belt has been acting up for awhile, i would keep greasing it and it would help for a lil while but then it would get stuck and keep grinding on me and i made due for awhile the best that i could but then i took my car in the other day for a radiator flush and after i picked it up, i opened my door and as the belt was retracting, the track on the inside rolled right out and i couldn't put it back in so my dad cut it right out.

I'm curious as to how hard of a job that is to get fixed? Can any regular auto shop fix this kinda problem and is it affordable?

Ok, Anyone at all gonna help me here?

I managed to buy bungee cords recently and hooked them onto the belt and underneath the seat so it kinda helps but it still tends to go off when i open the drivers side door only and as soon as i turn the key over, it immediately stops grinding.

go to a junk yard and get the complete belt assembly and replace it.Otherwise pay someone to do it for you.