"Why can't I see an emergency dentist?"

I am in severe dental pain and as I haven’t been to the dentist in a long time I’m not registered with a dentist. I called Liverpool's emergency dental helpline and was told that they couldn’t see me because I hadn’t been in pain for long enough- I would have to go to the pharmacist for stronger painkillers and try again tomorrow. I don’t feel that it’s fair that I can’t be seen now if there are spaces available and I have to continue with the pain.