wheel bolt broke. new disc?

[staticpat]

i brought my car to local wheel shop to get my new rim/tires balanced. the fuckers broke off one of my bolts claiming that the lugnut had been crossthreaded, im sure it wasn't though. i've had two bolts break off that disc before so i wasn't mad.
i think it may be warped or something, because the whole car shakes when i brake. whats the best way to fix this, im pretty sure it will happen again. i don't know a ton about cars, but how can i replace the whole disc, and bolts. can i just get one from a junkyard? or should i get it professionlly done

[BoredRec]

First of all the bolts, or studs as they are commonly called, aren't connected to the disc. They are attached thru the hub. Second of all your rotors are warped if you get a shake when you apply the brakes.
The stud isn't too bad, there are tricks you can do to make it easier, but it's probably best to have a mechanic do it, since they should know what they're doing.

[staticpat]

so what do i need to replace, where do they mount, in the rotor or hub or what? is it just more wothwhile to buy just a new bolt and lugnut for $3

ive replaced the bolts before, its not hard, im just concerned that they keep breaking (btw, the one that broke is not one that i replaced myself)