Hack a server?

So say a server has a member system where you purchase levels to go higher in rank, but there's only 2 ranks. The actual purchase made outside of the server on a website. Would it be possible to somehow trick the server into making you the highest level if you had access to one of the lower ranks? I'm new to server mechanics so go easy on me.

Nope, its through paypal mostly.

No. The server likely uses Groupmanager or some other rank plugin. You'd need permissions for that plugin to promote yourself.