If you're saying you did'nt have ads on your site and want to downgrade to static, I take it that you had an account that required ads? You have violated our TOS. Your account is suspended for 4 days, after which you may request a downgrade or apply the ads.
You will have to post in the upgrades and changes forum if you want to downgrade. You will have to wait untill the suspension is up. Im pretty sure this will be your last change, if you even recieve it. Please though, if you may need a database or more bandwidth, just keep your current plan.