for anyone having difficulties knowing if they are entitled to healthcare, and then what to do after they have it, here's my HOW TO GUIDE to the medical maze!
1). find if you are entitled to healthcare: if you registered here before abril 2012, earn less than 100K/year and do NOT receive healthcare from your home country, you are entitled according to this:
in english https://www.gov.uk/healthcare-in-spain
2). Go to the social security office and register, they will give you a number and mail you a letter. with the number you can register with a doctor.
3). you DON'T have to register with the healthcare centre (HC) that belongs to your address!!!!!!, so ask ask and ask, search the web, fb groups and forums asking for recommendations. Once you find a good recommendation and it's convenient for you go to step 4
4). go to the HC of your choice and register there, they will ask why you are not registering in the one that covers your affress, so print this and take it with you: http://www.juntadeandalucia.es/servicioandaluzdesalud/principal/documentosAcc.asp?pagina=gr_derechos_libreeleccion_2&url=derechos/LibreEleccion/GeneralyPediatra.html
this states that you have a constitutional right to choose HC, and GP.
this is a constitutional right, so I doubt that they'll give you trouble if they realize you have the information, but if they continue telling no, make a carta de reclamación, the SAS has a period in which they have to answer to complaints.
The ONLY cause to reject you as a patient for your chosen doctor is if that doctor has exceeded his/her quota, or if he has too many over 65 patients. the doctor does not has to authorize this.
6). in order to prepare for your first appointment, go to my blog post for a crash course in "medspeak"!!!!! :) http://compasshealthcare.blogspot.com.es/2013/03/get-most-out-of-your-doctors.html
I will update that post, but for now it can help.