Passenger seat belt mechanism sticking

No sorry I wasn't clear. I am talking about the mechanism in the body column that houses the take-up reel. I have since learned that the Matrix uses a pre-tensioner system which is constantly 'online' unless the battery is disconnected. It is integrated with the side impact air-bag system. (SRS). In 'normal' emergency stop mode it will lock and slightly tighten the belt around the person. In a crash, pellets in the take up reel ignite and a bunch of things happen. End result is the assembly has to be replaced. It is a 'hazardous' component and wisely left to mechanics qualified in dismantling and setting it up. One side effect is a film of dust is ejected into the passenger space. I mention that because when the take up reel started sticking when trying to pull it out to fix around a person I asked my local Halford's service station (UK chain) to look at it when they were doing some other work on the car. The mechanic hit it with hammer 'in just the right spot' and didn't charge me. Not long after it jammed up completely. But at the time I noticed my passenger compartment had this film of coarse-ish dust in it. In researching for this inquiry I discovered the use manual warns specifically against doing that because it is likely to ignite the charge in the take up reel mechanism and the result will be dust in the car and the whole assembly will need replacing!
The only concern I have, besides the obvious about Halford's competence, is that the car repair manual indicates that the status of the take-up reel mechanism, as being 'fired', should reflect in the display of the 'Air Bag' status indicator during the post-ignition check sequence. It doesn't indicate any problem. I will check to see if the belt is twisted inside the column. But if that's not the problem, and it doesn't feel like it is, then I guess I'm in for another big bill I can't afford.