Taylor59 on "2012 theme"

I set up WP with a hosting provider and had the 2012 theme.
I recently changed hosting providers and when they reinstalled WP for me and I logged into my site, it defaulted to the 2013 theme. I would like to use the 2012 theme. (There wasn't much there so the reinstall didn't hurt anything)
I did go into themes and chose the "activate" option and my site is now set to 2012. Do I have to do anything else so that this change is permanent, like FTP my WP files again?
Thank you for your help.