Is anyone here familiar with dental hygiene on a professional level?

Details: I went in for a routine cleaning when I got the bill it was called a debridedment and therefore not covered by insurance. They did nothing different than they have always done so I looked it up to find out what it was they were saying had been done. Supposedly it is much more thorough, more intrusive and therefore more time consuming while in reality it took less time than usual and there was less bleeding. Seems like every time I go in I have a different Hygienist so there is no consistancy in treatment.
What I would like to know is if there is a very specific, detailed and objective definition of the difference between a cleaning and a debridement or is it subjective?
One other note, they did not set me up for another visit other than a regular cleaning at 3 months instead of the regular 6 months.