Ok so I'm thinking you ended up signing up for Google Apps for Business like I did. Someone provided me with the information below. Since you're already set up and running, it should be easy to downgrade to Google Apps for Free. Once my trial ended, I had the option to delete my account or downgrade. Not sure if you have to expire first or if you can change it now, but hope this helps you.
RE: Google Apps - Free?
Google Apps does have free versions. http://www.google.com/apps/intl/en/group/index.html you can get started there setting up services for a domain that you happen to own. The options to use certain apps on DH just makes sure to input the proper settings on your account for records without you having to do it manually (which we use to have to do! and it was a pain in my butt).