The Dealership’s mechanic left the oil cap loose. Engine, belts were all covered in oil for 2 weeks. So far, the serpentine belt needed replacement. With only 18,000 miles, I am worried the oil damaged more. Dealer wiped visible parts of engine and filled oil, which was down 1/4.
Oil on belts is not a good thing, but that’s about oil there is to fret about. You might be entitled to have your engine steam cleaned. I imagine it looked messy at first but that’s oil.
Being low by only 1/4 quart will not damage the engine, and neither will some oil on the outside. I would ask for new belts, since they’ve been soaked in oil, but other than that you should be OK. I’m assuming they cleaned up the mess.
You didn’t say what kind of car you have, but if it has a timing belt, that also might have been compromised. The plastic cover is not oil-proof. Ask the mechanic if he’s willing to guarantee that it will not break, and if it does, that he will fix whatever it takes out with it.