Hi guys.
need help with what probably is one of a kind.

A while back our 2013 the Voyager brake master let go and i lost brakes, as i was pumping them up. Bang, the master locks up.
well that's what i thought, until i ordered a new master Cyl, as we went to remove the master, we found one of the bolts loose.
on further inspection we found that the bolt and nut was turning. This not supposed to happen.
After removing the nut and the master Cyl, the bolt fell out. The bolt had snapped of in side the booster.

So, in the last 30yrs in working and building cars, we have never had a boosters bolt snap off.

Now here is where im pissed.
1. i have to ether try and remove the broken part of the bolt out of the booster and hope it didn't penetrate the diaphragm.
2. replace the bolt (if i can get it fitted between the spring) and somehow stop it from turning while tightening it.
3. remove the booster and replace it with a second hand one. (this looks like i will need to remove/drop the engine to get the booster out.
4. seek legal advice?

any help would be greatly appreciated