"Access to disabled toilets"

I was visiting my  mother at the hospital last week and we decided to venture down for a coffee at the shop  by the canteen. All was going well until my mother needed to visit the local toilet facilities. So, we wondered over to the disabled toilet, because my mother was in a wheelchair she was unable to use the normal facilities. It was clearly noted on the door to get the key from the local reception desk. However, being on a Sunday said reception was closed. So, we had to cut the coffee break short and return to the ward. Surely access to disabled toilets should always be available especially within a hospital setting?