I've had similar experiences with a building maintenance company. Some guy came into my apartment and completely misused my private property during his work. There was a note left at the building with a phone number left to reach the employee in question - but they didn't actually pick up the phone. I presume that it was because they had already finished work for that day. I just decided to look up the company information and called the CEO, who promised to make it up for me, and did.