Hi Tammy,
So sorry you're having this problem but it seems to be a frequent occurrence in this business. As others have said, insist on a signed contract, 50% up front and never release the finished work until paid in full so you have leverage.
I once had an aggressive telemarketer, whose pitch I declined, ask "If I turned up at your place of business every day, would you like that better?"
I work out of my home and, uninvited, you'd be met with 100lb of teeth and fury dog and I'd call the cops ... suit yourself
Sadly, not only in business but in life itself, you will meet many individuals who have no class and even fewer ethics.
We professionals have an abundance of both class and ethics, so hang in there and don't let one rotten apple rain on your parade - you're worth so much more!
Lynne