Amazing.. while i don't know Manchovie from Adam, i could certainly understand his frustration to throw 1/2 your money back at you just to be rid of you.. i'm surprised that he didn't throw anything else, frankly. I'm getting that from YOUR post bdot, not from his input on this.
If you started harassing me via texts and what-not, like it sounds like you did, i think i likely would have shipped you back your guns free of charge way before any 'deadline'.. in their component pieces, packaged neatly in plastic baggies, for you to deal with it.
Your posts give me a headache to interpret, but if i understand correctly.. he gave you back a gun, on the deadline date, and it was working in his residence when you test-fired it.. it only broke when you decided to fire it (!!) in your car?
If the above is correct, then all he owed you was a "too bad, so sad". Parts unrelated to repaired/worked on components can break out of the blue.
Like you, i consider this a 'hobby'. I've only been into it since mid-summer of 2010. I could afford very easily to go to a gun-doc if i so choose to do so. I don't.. i roll up my sleeves, and i learn. I've got 2 AEG's that i've pulled apart numerous times in their short lifespan in my grubby mitts. I've broken a few pieces, and i've learned not to break pieces as a consequence. I've certainly not spent $140.00 on replacement parts, as part of that learning process.
I think that you are going to need to learn how to work on your own l33t magpul crap, just like i've learned to work on my own pedestrian, humble AEG's.. no gun doc is going to touch you with a 10 foot pole from here on out.