If someone is repeatedly making false KOS's, you are free to report them here on our forums in the
REPORT ABUSE section. If a staff member is online you can put a message in admin chat by doing '@ message' to bring this to their attention and they can take the necessary action. Make sure you include all proof you have, preferably video evidence. A staff member will then be able to look into this for you.
Apologies for any issues they are causing you, I will also alert staff on discord that help may be required.