I think I know the DZ that you're referring to and I too have worked there. If so, you DID sign a non-compete agreement when you started working there. Now sure, that might sound crappy, but if I recall... they've had former employees move to the competing DZ and call/email all their former students to bad mouth the old DZ and bring them to the new. Have you done that yet? Were you thinking of doing that? Don't lie.
Sure it sucks that someone had to threaten to enforce the agreement that YOU SIGNED. To me, what sucks even more is that a man who makes an agreement can't abide by the terms of that agreement and instead decides to whine publicly when it is enforced.
Wouldn't it be great if people just had the honor to do what they agreed to do in the first place?
Good luck!
