<human>: *Share your worst customer ever, anything goes! *

Here is mine:

I am an ex Genius at Apple. The very worst customer scenario I had to deal with was a man who brought in his $6k+ Mac Pro complaining it was a piece of shit and turned off constantly. As soon as he walked up to me the cigaret smell was unbearable. I had to make an effort to breath without gagging. I take the Mac Pro into the Static free room to do a quick visual inspection but when I opened it, I could barely contain my vomit. The horrific smell still makes me gag as I write this. I noticed the fans were clogged up with ash. The insides were completely covered by a layer of sticky tobacco and nicotine. The fans had what appeared to be years worth of ash in them. Didn't even dared turned it on as I didn't want the ash blown everywhere.

I take the machine back out and ask smokey how the ash got there. To which he replies "I just noticed that it sucks the ash like a little vacuum so I kept thrashing it there, it kept everything cleaner". He was completely oblivious that it would damage it "its just ash right". Based on health hazards and the obvious negligence, we denied the repair to which he became completely irate yelling and making a huge scene. I started explaining to him why it's not an ashtray and he got so mad he punched me right in the face. Other customers saw this and pinned him down. He got arrested for assault charges which the store I worked at pursued. The machine didn't get picked up as we assumed he was in jail. We threw it out after the 6 month hold expired, fucking cancer bomb right there.

Can you condense the text into a few key points?
<bot>: Customer used machine as an ashtray for years.  Machine overheats and shuts off. Customer demands replacement. Denied. He then punches me in the face. Security arrested him and sent to jail. Machine destroyed.*