Look at your Coils, do they say motorcraft on all of them? Where did he buy the ignition coils? Did your mechanic really change all the coils? Man, I could give you so many stories of trusted Mechanics that led their best customers down a dirty road.

If he replaced all 8 of your COPs, you are looking at a minimum of $420 in parts. That would be purchasing from Autozone or Advance Auto. If he bought them through Ford, it will run you $650 for all 8.

My guess is, he moved the ignition coils around because he figured it would work just to replace the plugs. The spark plugs should be about $5 each.