The subscription box is an Amazon-run program which means you will need to log in to your Amazon account to cancel that.
To log in to your Amazon account and cancel your subscription:
1. Go to Your Memberships & Subscriptions.
2. Find your Subscription Box subscription and select Manage Subscriptions.
3. Select the desired change and follow the on-screen instructions.
Note: Canceling your subscription does not cancel any unshipped orders that may already be placed.
If you are still unable to cancel your subscription, we recommend reaching out to Amazon directly via their customer service line and they should be able to aid you in canceling your subscription entirely.
Amazon Customer Service Line: 1-888-280-4331
https://www.amazon.com/gp/help/customer/contact-us?referral=A30O0NPDCBN76I_A1PUL3LQT4ILPV