I had this electrical issue with my Benz a few years ago. It was covered under warranty. After the dealer fixed the issue, the SA called me and asked if it was ok for the tech to take it home for the night just to make sure the issue was fixed. He put about 100 miles on it and went through a Jack in the Box drive thru (dash cam footage). Because they asked for my consent to take the car out, I had no issue with it.
If the 400 miles or what they did with the car during that time was not a necessary part of the repair, I’d be heated. Legally though, “hurt feelings” isn’t compensatory. You gotta show actual damage, which you haven’t specified in this thread. From a customer service stand point, they should make it right for you. But be reasonable or you’ll get nothing.