My wife took her Buick to Jiffy Lube in Odessa for an oil change once, and they informed her they were out of the filter she needed. They changed her oil anyway, and told her if she went to Auto Zone or somewhere and bought a filter, they would gladly put it on for her. When I got back to town, I took her car back in there so I could watch them change the oil and filter with the branch manager standing next to me. I even got a refund for what she paid. Needless to say, we never used that place again.The one time I had an oil/lube place do my oil, when I got home, I discovered my filter hadn't been changed out. Plus, I was supposed to have Mobil 1, but I thought if they cheated my on the oil filter how do I know they didn't put crap oil in my crankcase. I didn't watch when it was done.
I negotiated they change out the oil (again) while I witnessed it, Mobile 1 out of cans, not some big bulk dispenser, plus of course a new filter. The guy dong the oil and filter was the same guy acted like he wasn't chagrined when caught and having to make it right, but he was. I went to his boss to complain and he was agreeable about my witnessing the ah, ahem, correction.
Of course, I learned my lesson.