I cannot get rid of it. That is stupid and terrible. "knotes" *MUST* have a simple, obvious way to make it shut down and go away. *ESPECIALLY* since the process it uses does not include "note" in its name. (Thus, "ps -ef | grep -i note" does no good.)
Are you sure you are using knotes and not Plasma note widgets?
If you can provide the information requested in comment #1, please add it.
Um, I can't because I do not know. How can I tell? Given that I cannot find any process with a name that contains "note", I'd guess that it was a widget running under KDE. Same comment, but different people. Sorry.
To close a Plasma widget, keep the left mouse button pressed until the toolbuttons appear, and click on X. The widgets need to be unlocked for this to work.