I'm not banned but it says Flying is not enable on this server every time i try to log on?

 

It's the current anti-cheat. This thread explains why Anti-cheat | Skyblock Forums

You can ask a moderator to teleport you to them and it will not ban you. It is a current bug which should be fixed soon. You can message any moderator to request them to do that and plan out a time for that to happen.

 

I can't even get on the server

 

The anti-cheat was removed, you should not get kicked for flying anymore.