Go to the surgery and ask to speak to the practice manager, when asked what for, tell them you want a copy of thier Complaint's Procedure.
Follow the procedure to the letter and keep a copy of everything, they have 3 days to acknowledge the complaint.
Lay out the fact you have the CHOICE of where your treatment is carried out and that the GP in refusing to refer you breaks the
NHS charter and unfortunately this is causing you undue stress and concern for your health.
If that fails to move anything then give one of the ambulance chasing medical negligence law firms a call and see if they will take you on in a no win no fee, that will most certainly get the surgery's attention as a legal case will cost more than sending you to a hospital more expensive than they are prepared to write you up for.