In the Settings option of Nelio Content you can delete a social profile from Nelio Content. Doing so, nobody can schedule new social messages nor any scheduled message will be published. However, Nelio Content will still have access to that account, since you can have other websites that do have configured that profile and thus need to post messages on it.
To completely delete Nelio Content permissions on Pinterest go to your Pinterest account (in the Pinterest’s web) and select Settings. In this new window, at the Apps tab you’ll see the list of apps that have access to your account.
Click on the Revoke Access button next to Nelio Content and the permission will be revoked. Of course, you can always return to give Nelio Content permission to access Pinterest.