When organisations provide services to the public - whether businesses, state agencies, or NGOs - people often need to be able to talk to a human there to get ... well ... service. At a time when it's increasingly difficult to go to a building with a reception area staffed by a human, it's unacceptable to make people wait on hold when they call.
When a callcentre can't answer immediately, they should be legally obliged to tell us so when we call, record our number, and call us back.