They used to be good but now they are mediocre. Th...

They used to be good but now they are mediocre. They are too busy to do good work. They often make mistakes. My 2015 Mack truck was in their shop Friday June 16th. I gave them a printed list of things I wanted performed on the truck. I also gave them a copy of the Mack Service Bulletin, which describes how to fix my problem (power loss due to air in the fuel system). They also made a copy of the page from the Mack Operator manual; which describes how to perform an anti-corrosion protection on the truck. I also gave them verbal instructions. Result? A $1500 bill and only 3 things out of 6 on my list were done. Instead of anti-corrosion protection of the electric system, they installed a battery protection harness. They didn't follow the instructions on the first 4 pages of the Mack Service Bulletin ('air in the fuel system'). Instead they did the standard tube test, which - during my verbal instruction - I told them would NOT work (the tanks had a lot of fuel; the system was primed on the previous day; the power loss does NOT happen where the tanks were almost full). To cut a long story short; they failed to follow my requests, performed wrong work (battery protection harness instead of corrosion protection grease), and only solved 3 problems out of 6. All this happened despite me giving the shop both clear written and verbal instructions.