If you have already been charged for a specific box (Pop Culture or Horror) for that month, changing the subscription type (i.e. Pop Culture to Horror) will change your subscription type on the next renewal. Once you have been charged for a box that is the box you will receive.
If you do not know how to change your subscription type, here are the steps on how to do that:
1) Login to your account from our homepage, and click on the MY ACCOUNT tab.
2) Under the subscription information, click the EDIT button.
3) On this page you can change your subscription type.
4) Click on the subscription type you want to change your subscription to, and save the changes.
Your next renewal will reflect the subscription type change.