I bought a small ceramic coated pan about a year ago. (Specifically this one)

When I just had it life was great. It worked very well for almost anything. Now it's a year later, there are some black spots on the grey ceramic, and it's impossible to fry an egg without having it stick. Even if I use insane amounts of oil, no matter how I cook it, it seems to stick. Where it sticks doesn't really seem to match with the black spots.

I've tried scrubbing it with soda, putting vinegar in it, even ammonia. Ammonia made the bottom side nice and shiny again, but did little for the top.

Is there a way to restore the pan? Is there something I'm doing wrong? Do I need to cook differently in a ceramic pan vs teflon?

Thanks for helping out!