Unfortunately the world is more and more packed with people who only understand "brute force" and who are resistent to any kind of reason.

Here is a way how you get rid of stockphotomedia

1: tell them by mail that you forbid them to sell any image which is longer than 6 month in their database. Put your lawyer in CC and tell them that you step into legal action without any warning if they sell one
2:  tell them by mail that they have to delete your account latest 6 month after your last upload . Put your lawyer in CC and tell them that you step into legal action without any warning if your account is still active after that date
3: Edit your profile and write "Dear Customer, you should better buy our images at SHUTTERSTOCK or any other serious agency"
4: Create a mail signature with a part like this: "DONT SELL / BUY IMAGES AT www.stockphotomedia.com" , link to this thread and tell them that you gonna leave that in your mails as long as they leave your account active.
5: use a bulkmailprogramm to ask them in very small intervalls for a confirmation and send this mail to as much stockphotomedia-accounts you can find. short down the sending-intervall a bit every hour.

in our case they confirmed quite early.
we only had to ask around 800 times until we got the confirmation.

And folks - i know much more of even worse legal tricks to annoy people like they are.
I definitely hate these "wannabee-Bonapartes" with their mean hostage-strategy