Why is the name wrong in the directory, or the wrong name shows up when someone calls? Local directory entries on the phone override global directory settings. If you put a directory entry on the phone, the number will be associated with that name even if the global directory name changes.
For example, An entry for extension 2299 named Roberta Cat is in the local phone directory. The global directory has an entry for Charles Anderson Tilde for extension 2299; it will still show as Roberta Cat instead of Charles for the number 2299.