You may wish to send a letter, or perhaps better have your lawyer send a letter, describing your intention to remove the fence from its present location and place it along the property line (in accord with any setback requirements), if they don't do so themselves by a specified date. If you move the fence yourself, presumably it would end up on your side of the property line as you can only authorize the workers to enter your own property. A local real estate lawyer should be able to clarify your rights, and help you formulate the best possible plan to bring closure to the issue.

