1992 Pontiac Transport CRANK SENSOR

Hi Kattieann,
It's possible the fastener is stretched, galled, etc. If "they" already know this and are still having trouble they could try to give it a sharp tap to "shock" it. There are also new kits on the aftermarket that "freeze shock" the fastener which are much more effective. Just remember a mistake here does expensive damage to your crankshaft/engine. Make sure the people working on it are experienced automotive technicians to avoid compounding your problem. The proper type of puller is also a good idea here when the fastener is loose. If "they" are a reputable repair shop I would suspect they don't want to take responsibility for the possible damage I refered to. It is possible that the bolt is seized or otherwise damaged and will be a risky procedure to attempt to replace or repair.
If this is the case; be understanding, make sure you have faith that the best auto technician (mechanic) you can find is doing the job, and be ready to accept the fact that it may not work out well in the end. Most Techs I know will give it their best shot if they know you understand the odds are against you. I recommend asking if this is the concern and trying to find a workable agreement.