If you signed up for CBS All Access via iTunes, and you would like to cancel, just follow the steps for your device:

On your iPhone, iPad or iPod touch
  1. On the Home screen, tap Settings.
  2. Tap App and iTunes Stores.
  3. Tap your Apple ID. 
  4. Tap View Apple ID. You might need to sign in.
  5. Under Subscriptions, tap Manage.
  • If you don't see a subscription in iTunes and are still being charged, make sure that you're signed in with the correct Apple ID. If so, you might have subscribed directly with the provider and not through iTunes. In this case, please contact the content publisher or app developer directly to cancel your subscription.
       6. Tap the subscription that you want to manage.
       7. Use the options to manage your subscription. You can choose a different subscription period, or turn off Automatic Renewal.

Turn off Automatic Renewal to cancel a subscription. Your subscription will stop at the end of the current billing cycle.

On your Mac or PC
1. Open iTunes.
2. Click Sign In and enter your Apple ID.
3. Click your name, and select Account Info from the drop-down menu.
4. Enter your password again.

On the Account Information screen:
1. Scroll to the Settings section. 
2. To the right of Subscriptions, click Manage.
  • If you don't see a subscription in iTunes and are still being charged, make sure that you're signed in with the correct Apple ID. If so, you might have subscribed directly with the provider and not through iTunes. In this case, please contact the content publisher or app developer directly to cancel your subscription.
3. Choose the subscription you want to manage.
4. Use the options to manage your subscription. You can choose a different subscription period, or turn off Automatic Renewal.

Turn off Automatic Renewal to cancel a subscription. Your subscription will stop at the end of the current billing cycle.