If you signed up to Antstream Arcade and set your payment method to PayPal, this is how to unsubscribe from the recurring billing.
Step 1) Log into your PayPal account.
Step 2) Navigate to settings.
Step 3) Select "Payments".
Step 4) Select "Manage your pre-approved payments", which will bring up the following menu:
Step 5) Select the merchant "Microsoft Corporation", which will bring up the following menu:
Step 6) Select "Cancel"
Step 7) Confirm the cancellation. This will stop your recurring payments to Microsoft, and your subscription to Antstream Arcade will be cancelled and you will not be billed in future.