We do not lock you into any contract nor do we lock you into a specific billing cycle. You can choose to pay monthly, every 3 months, every 6 months or every 12 months. Choose the payment terms that best suit your individual circumstances. You are not locked into any particular payment term.
You have been paying using the 3 months option but need to change to a monthly plan. You simply have to go to your Account Control Panel (not cPanel) and change the terms in the products/services section.
If you are upgrading an account, you will be invoiced for the new amount minus any payment for that particular month on a monthly account already made, or minus the amount paid on an annual account.
If you are downgrading your account you will get credit for the amount over that has been paid on the monthly account or annual account.