How Can I Convince My Dermatologist To Help With My Skin?

What can i say to make them help me? ..
i visited a derm and talked about my premature wrinkles at age 22… which is not normal. and he didn't offer help, just told me to go to the beauty shop and ask. But the thing is i have psoriasis patches on my face, and he doesn't believe me and say its not. When it clearly is, and i even show him pictures to prove it… if its not patches then why does it look flake and its always there? ..

anyways, we ended up arguing… and so he didn't help me! Im referrred to a different dermatologist now, but i hope this other one can help me. Whats wrong, why they not help me?