Create users using API gave me error to access

Hi keap team, I try to create users using your API user but I can’t se how delete this user or update, that endpoint does not exist? also a got a lot errors when try to re-create this user after inactive it, now i got error like “We were unable to connect your Keap ID to your account because your Keap ID is already connected to a different user in this account. Please contact support at 1-866-800-0004.” when try to login for example