I don't understand what those employees were doing, or why. But I don't like that your experiences of being bullied have been negated over the years.

One more thought I have is, are you sure those employees weren't coming on to you in a very clumsy way? My experience with people being singled out and observed is that they are being hit on, or flirted with. Plain or unattractive people are usually just left alone - by adults, anyway.