I don't think it really matters. Just call and if you want to talk to the guide they'll connect you or have him/her contact you. (tomorrow, as they aren't open today)
But from your other post, I don't think you NEED to talk to the guide; I'd go resale.
LOL! I agree with Ben E N. Members Services has ready access to your guide's name and toll free number. It likely is also on some of the DVC emails you receive.