No problem at all! As long as we haven't sold out of the current box, all you need to do is email firstname.lastname@example.org. We will be able to manually renew your account for you so you don't miss out on the fun!
Please do not purchase another subscription. This will create two subscriptions under your account, and can cause quite a bit of confusion (and you run the risk of accidentally being charged twice the following month). Just email us and we'll help you out!