I recently had a good experience with Jim Keim Ford in Hilliard OH. They charged me a diagnostic fee to replace the fuel pump under warranty. I was in a hurry picking it up so I didn't dispute it then.
Later a girl from the dealership called and asked how my experience with the service was. I told her about the fee I was charged and she told me the service manager would call me back that day. He did, and agreed that he thought the fee was inappropriate. After speaking with his techs, he called me the next day and told me they were cutting me a refund check.
I think the trick was that I was calm and didn't assume that they were out to get me. I told him I thought it was just miscommunication between the counter guy and the tech as to what I wanted.
Panties aren't the best thing in the world but they are next to it.
I would rather drive the slow car Rusty built than the slow car I built.
Do your own repairs, it's not rocket surgery !!