Shiptheory allows you the ability to change between plans at any time, upgrading and downgrading, switching from monthly to annual, or annual to monthly at any point you'd like. At the time of moving plan, you will credited pro rata any credit you may accrue from the down or upgrade.
Any remaining pro rata credit will remain in your Shiptheory account for you to use at a later date.
Unfortunately we are unable to refund you any credit you have that may reside in your Shiptheory account, unless we've previously agreed to do so with you in writing.