The Goddess Relief Office is the agency that Belldandy works for. It is a heavenly service that filters our acceptable mortals for divine workers to grant wishes to, and intercepts them at some point of their lives in order to grant said wishes.
It should be noted that there are more than one type of this sort of agency. The only other one available right now is the Earth Assistance Hotline, which is a rival agency and is the agency that Peorth is employed by.
There are various other translations for Goddess Relief Office, among others Goddess Technical Help Line, Goddess Relief Line, Helper Goddess Office and probably more.