You can remove your automatic payment method at any time.

To remove your payment method information:
Go to My eBay.
Click the Account tab and then click the Personal Information link on the left.
In the Financial Information section, find the payment method you'd like to remove and click the Remove link on the right.
You may still accrue fees for any listings you have on the site, as well as monthly fees if you have any active subscriptions such as eBay Stores. Make sure you cancel any subscriptions if you want to close your account.