It drove me absolutely nuts when my company was blamed for the customer’s pre-existing problem(s)! However usually they (and I) were innocent victims of a weird psychological phenomenon I’ve dubbed … “Heightened Awareness Syndrome”! (HAS)
A wise businessperson knows which fights are worth fighting. Your highly trained service technicians specialty should be making the Cheerleader for future cleaning sales. Support your crews (and avoid headaches) with this System.