hookup.com melissa parkerjohn salenga asked for money for service and did not comply and wont refund money. threatening to post things about me. Internet

i contacted this site to set up a date with a model.  i sent payment as requested and never met with model.  i asked for a refund and they are threatening to post items about me if i dont pay the extra 100.

 it was for 1000 and i paid 900.  i am willing to let go money and forget the whole thing and chalk it up to a learning expirience.  but now they wont stop sending me threatening emails.

 not sure what to do except cancel my email account.  but i dont know if that will work and i want to put this out there so others wont be suckered as well.