I don’t think it has to be easy, these are tough jobs. So are most jobs, and mistakes do happen. But I don’t think there’s anything wrong with expecting the service that the company is offering to actually be performed to completion. I get it’s tough working in something like an oil change place, but promising to do the whole job and then deciding to not do some part of it because “things are seldom so straight forward” would not, I’d hope, be acceptable to anyone involved.