If you are using an Apple (iOS) device and would like to change your subscription, please go through the following steps:
  1. Open Settings in your device;
  2. Tap iTunes & App Store;
  3. Tap Apple ID: (your email address);
  4. Tap View Apple ID;
  5. Under Subscriptions, tap Manage;
  6. Tap Massive Warfare: Aftermath;
  7. Select the subscription you want to change it to.
The new subscription will take effect and be charged accordingly after the current period ends.

If you are on a Google (Android) device, please cancel your current subscription and subscribe to the desired one!