"Discriminating against the most vulnerable"

I have a life threatening condition and rely on regular follow ups at Moorfields. My condition can deteriorate quickly and Moorfields has always told me I must return immediately if there are changes, because these could be fatal. But since Moorfields found out I am exempt from covering my face by way of disability, they have treated me like dirt. First they pressured me into getting a doctor's exemption letter even though government rules say you don't need this. My nhs gp said they are not doing letters, because the law says you don't need one. I told him Moorfields is insisting on it, but he said Moorfields is not allowed to do that. So I had to get one from a private GP and it cost me almost two hundred pounds! Moorfields threatened not to allow me in unless I showed the letter. Now I've got the letter, Moorfields says they might not allow me back anyway because of my exemption! I'm appalled by this, Moorfields is punishing people with disabilities and openly saying they may not receive care, or will receive a lower standard of care (eg by phone, when I need physical tests on my eyes). How can this be allowed? People who cannot cover their faces are the most vulnerable and Moorfields is treating us like dirt. Why make me run up costs for a letter as a condition of being allowed to attend my appointment, then tell me you might not allow me in regardless? Everyone is struggling financially, I could have bought groceries for a month with that money. I've seen other reviews saying this discrimination against goes against the Equality Act, but I am too sick to take it further. Shame on you Moorfields!