As the previous person mentioned, suspended accounts need mod intervention. If you have already paid for your renewal (Autopay or otherwise) if you were to change the plan yourself you would lose the money you paid towards it and instantly start on the new plan unless you schedule it for your next renewal date. The mods need to adjust your account for you to prevent the loss of funds for a between renewal dates switch.
To change a plan you have to log into your "My Account" (Self Service) and the line directly under Account Status tells you your current plan. There is a button on the right side of that box that lets you change your plan. (Again assuming your account is active).
