Problem connecting site to market place

Permalink
Hello, I'm trying to purchase a new add on to an old site. The site was connected to a concrete5 account that's not existing anymore and I have also copied the site to a development area. I.e. created a sub domain dev.thesite.com instead of www....

Now, as the site has been connected to a concrete5 market place it naturally wants to connect using that account to get the add ons. But I don't know the login details, and it won't let me sign in with my new ones.

How do I get around that?