(a) When a guardian has given such bond as may be required and the bond has been approved, as provided by § 28-48-205, or if no bond is required and the guardian has filed his or her written acceptance of his or her appointment, letters of guardianship under the seal of the court shall be issued to him or her.
(b) The letters, when so issued, until revoked or cancelled by the court, shall protect persons who, in good faith, act in reliance thereon.