I've six 123s and the alignment problem is almost always the technician. If you've the printout from the first time, I'll bet it won't agree with the prealignment printout when you take it back the second time. If I'm correct, it's the tehc. I went through this same thing three times with Wheel Works before taking it to another of their branches where the tech knew about MBs. He got it right. Now I always take it to that shop but only when he's on duty. Hope this helps.
Ben
www.reproduce100s.com