Maybe this is part of the answer? No one co-ordinated a special public awareness campaign which educated the system abusers about how 999 react to "chest pain", it just spread about. So maybe if fines for really inappropriate use of the ambulance service were simply introduced, quietly, then knowledge of that would just spread about - without scaring elderly/vulnerable genuine callers with a "hard-hitting" series of adverts to which the service abusers won't pay any attention.