(1) The registrar-general shall cause a copy of each notice required by this Act to be served on, or given or sent to, a person, to be filed with a memorandum of the notice having been so served, given or sent and the memorandum shall be sufficient proof that the notice was duly served, given or sent.
(2) When all reasonable efforts have been made to serve, give or send a notice on or to a person in accordance with this Act and the person cannot be located, or the registered letter containing the notice has been returned, the registrar-general may—
(a) cause a further notice to be served, given or sent; or
(b) cause substituted service to be effected; or
(c) proceed without notice.