Free healthcare

Hi All, I'm under retirement age and when I first became resident in Spain four years ago I took out private medical insurance for the first two years. Then I was told about free healthcare for all residents in Spain through a royal decree regardless of age. So I went along to my medical centre with my residencia card and padron and applied for free health care. To my surprise it was sorted out in minutes and I was given temporary health care free for twelve months and was given a medical number and was signed up with my local doctors. I applied again  after twelve months and the cover was extended for another twelve months which ends this month. I returned today to the medical centre to renew for the next twelve months and was refused. The reason being they said it should have only be granted for one year only. This is not mentioned in the Royal decree. They have told me to either pay into the system through the Convenio Especial scheme or go private. Has anybody else had a similar experience?.