Banned on private server

[geetech]

So i was stupid and got banned on a private server.

Im apparently not ip banned. But whenever i make a new account it gets banned 1-2 hours after i logged in.

What can i do?

I have already tried to use 5 different VPN.

Ive changed my MAC adress

Ive removed the entire folder with the server and re downloaded it again

Ive heard that they sometimes leave a file on your pc to check if the user is banned.
Or that they "flag" the hardware you are using.

I have logged on my laptop without any vpn or anything and that account doesnt get banned.

Any ideas?