If at the expiration of the time set in the notice provided for in the preceding section the person so notified shall have refused, neglected or failed to comply with the request made in such notice and shall not have torn down or changed the fence or wall so as to conform to and comply with the provisions of this article, the director of public works shall have authority and it shall be his or her duty to proceed forthwith to tear down, or cause to be torn down, such fence or wall or so much thereof as is being maintained or shall have been erected and constructed in violation of the provisions of this article, and the cost of such tearing down shall be charged to and recovered from the owner of such fence or wall or from the person for whom such fence or wall has been or is being erected.