Sometimes it's obvious if an ambulance is needed. Mum collapsed a few years ago and if Dad had taken her to A&E she would have died on the way. Because she was in an ambulance the Medic was able to clear airways etc etc and she made it to hospital alive.
St John ambulance saved my mothers life and I will forever be grateful. They are legends.
Having said that TTK, it sounds as if the person you dealt with had the wrong attitude and I'd mention it to someone. One shouldn't be made to feel like they were a nuisance because it may cause them to hesitate to ring the next time.