I had mine done at sears and asked before hand if they could do a custom alignment and were able to work on aftermarket suspension parts. They did a great job but there was one guy specifically who I was told was the only guy who could do it.
The camber arms should have been as easy as them turning a lock nut, then turning the adjustable body of the arm. Watch the wheel move and lock it down when its in spec. You could do a better job in your driveway with a digital level. He just turned everything the wrong way.
The fronts are trickier. If you only have one set of bolts in, they need to loosen both sets, turn the SPC bolt, then lock down both. If they turn the wrong one nothing will happen and they will say, eh it doesn't move thats it. Basically half-assing it.
-6 is ridiculous. That's visibly wrong as you noticed. I'm honestly mad for you. That's some lazy BS right there. Hope you find a good shop man.