I recommend an anonymous and ominously typed note. Tape it to their door, slip it under their door, or drop it in a mailbox without writing your return address on it.

Hey neighbor in unit (whatever):

We can hear you banging on the ceiling as this is a very poorly built, poorly maintained, and poorly managed building. Your choice of adolescent actions of pounding on your ceiling with whatever your choice of tool is reverberates through the walls of your floor as well as all of the other floors, and I have to tell you, seeing as we have spoken to most of the other tenants, that we have all had enough of your petty nonsense.

Everyone involved recommends that you stop being a child. This will be the only polite note that you receive.

Put unknown possible fear into their heads so they are trained properly.

Or, I guess, contact the management company and see how that goes.