linking old dashboard with new

Hi there,
Here’s my trouble, I’m not sure if this has been written about already but either I can’t find it, or my troubles are unique…i don’t know which is worse… ??
I registered my blog with the free .wordpress.com and posted blogs and received comments etc for a week or so. Then I bought the domain name and set up the site again. I remapped the free site over to the new paid domain one but the dashboards don’t link and it keeps jumping from the dashboard of the old one over to the dashboard of the new one. Sometimes it wont let me go to the old one and sometimes it wont let me go to the new one. Its very strange.
So i’m not sure how to solve this and so I’m appealing to the wiser masses.
Thanks!