Call the attorney, ask for a copy of retainer. The attorney may not show it to you since it is privileged. Next, ask for a rep letter from the attorney. Once you have the rep letter, ask a third person personally deliver to the attorney. Or else, check your state law if you can mail, email, or fax it to the attorney. You cannot do it yourself and must have a third person to do it. Make sure you keep a signed copy of the proof of service.