You need to find the original source they are using. Start with checking openstreetmap. If it's there you can edit it yourself (or add a note that it's wrong).

You need to find the original source they are using. Start with checking openstreetmap. If it's there you can edit it yourself (or add a note that it's wrong). Keep in mind that it likely originates from your town/county/state/country surveyors map and you'd need them to correct it in their systems, or it would probably be added again or the modification reverted.