I think, but am not positive, that the guide is probably the one assigned to the original purchaser. If you don't like your guide, you can request a new one.
However "guides" and "Member services" are two different things. Guides, basically, are the contract salesmen, you contact them to do contract add-ons.
Member Services is a call center set up similar to Central Reservations, you simply call and talk to whomever answers the phone.