Pro Sites not charging correct amount for website

Hello,

I am using Pro Site and new Blog Template on my multisite platform http://www.sensites.com. I had the monthly pay to blog level set at $19 per month. I just changed it to $59.99 and now all my clients (new and previous) are being charge $38.98/mo.

Why is this not the $59.99 charge?

I apologize for not being able to provide Support access to this site. I actually have a plugin conflict that I am trying to figure out that creates a 501 error when I activate the WPMU Dashboard.

Thanks,
Chris