Cannot log-in to admin

I am a non-techie with a new site. I uploaded and activated the free Flexibility3 theme. I worked on it a bit last night and everything seemed okay. Today when I try to log-in to my admin to work on the site, a white page comes up with the message to click to buy the paid version in order to remove footer links. I don’t care about the footer links but do want to be able to log-in to my site. I can find no way to eliminate this page. The log-in screen appears to flicker briefly beneath this unwanted page but then the page takes over. I have also tried to type in my log-in url directly but the same thing happens. It’s like this theme has hijacked my log-in. I had briefly used the same theme on a site that is no longer active and had no problems like this. Any ideas how to get rid of this (non-techie)? Thanks.
http://www.dogtailsfromthebarkside.com