Refuse to deliver parcel twice because of school holidays

I ordered a parcel for my father who is in hospital to be delivered at the school where my mother teaches. Dawn Wing did not attempt to deliver the parcel because it is school holidays. I called them and explained it is a private school that is not on holiday right now. They said they will deliver the next day. When I called them today they once again told me that they did not attempt delivery because it is school holidays. This is unacceptable.