Well, Brandon Satan is of course denying the work. The service advisor there, by the name of Bob, was pretty reluctant at first, but when he took the time to listen to my side of the story, he seemed to kind of understand the possibility of them possibly making the error. Bob isn't allowed to make the call of whether or not the dealership will cover it though, so he got his service manager involved, by the name of Lee.
When I first saw Lee coming out, I could tell he had an asshole swagger to him. He asked me "who are you!?" in a very rude tone. I told him who I was and explained the situation. He wouldn't even let me finish my sentences without cutting me off and continually shaking his head. They keep claiming that the bolt is not a "Mitsubishi" bolt. I told him I find it odd that it took them 3 days to tell me it wasn't an official bolt. He kept rambling on and basically stated they are not going to cover the work. He continued to cut me off, so I eventually yelled at him to listen to me and to quit cutting me off. At this point, Lee told me to leave the premises or he would have me arrested.

These guys are total slime balls and I must say, that he truly is the right guy for the position. This guy is so close minded and his customer mannerism down right sucks.
I'm probably just going to get the car out of there anyways and take it to someone much more reputable like the Brothers. Do you guys still think I should try to keep fighting though and make them eat the $500.00 in labor they charged me to open up the head? I know deep down, that their tech had to of dropped the bolt in there. No one else has ever worked on that car since I've owned it, except that dealership, and I got all the service records to prove it. I technically think that they should be covering the costs for everything, since this shit wouldn't even be happening if a bolt hadn't been laying in there, but at this point, I'd just be happy to pay the Brothers to do a good quality job on fixing the problem.
Would it be worth it to maybe take them to court? I suppose that I do have "circumstantial evidence" with my printed service records.
Their argument is that there is no way a bolt could have been lodged in the intake manifold or valve chamber for 20,000 miles and then it all of a sudden gets stuck in a valve. Keep in mind that this was a pretty long bolt that they found, so I could actually see it being stuck in the manifold this whole time and it finally managed to wriggle down through one of the intake runners, and it may possibly even of been rattling around the valve chamber for some time now.
Well, if there is anything to be learned from this, DO NOT take your car to Brandon Mitsubishi for work. They will lie and cheat their way out of anything they did wrong. I plan to lodge some complaints elsewhere as well and will type up a nice long detailed story at ripoffreport.com.
I believe we can officially give Brandon Mitsubishi the moniker of "Satan" and add it to the continually growing lists of other Satan Dealerships.
By the way, if anybody personally knows the Brothers (I already PM'ed them), can you tell them to PM me when they get the chance. I tried their number they gave me a while back in a PM, but it's no longer working.
Thanks for your all's time folks.