"The rudest, most degrading service I have ever..."

I brought my friend here on Saturday morning because she was having a severe Vertigo episode. She could barely stand up and walk when we went into the centre at 10am when it opened. She has been registered with the NHS for 20 years, is a British citizen at the highest tax band. The member of staff at reception said they cannot find her on the system. We called 111, they found her in less than 30 seconds. The 111 nurse asked to speak to reception. They still refused to serve us even though the 111 nurse confirmed that she is registered and has been for a long time. We showed an EU card and they still refused to serve us unless we pay £75. The 111 nurse directed us to a different hospital where I am now. I plan to write a complaint.