You can delete your pledge to a creator at any time. To do so from the mobile app follow these steps:
Step 1 - Click Account on the bottom-right of the app
Step 2 - Click Your Creators (3rd option down), which will pull up a list of everyone you are pledging to. Select the creator you wish to delete or edit a pledge for.
Step 3 - Now that you're on the creator's page, at the bottom of the page will be a recap of your existing pledge. Click this.
Step 4 - From here you can change a few different elements of a pledge:
The dollar amount you are pledging
Your desired reward tier
The payment method used to pay for the pledge
Delete your pledge
Step 5 - To delete your pledge select "Delete Pledge" at the bottom, a new window will show that asks if you are sure you want to delete:
and a big orange button that says "Delete my pledge"- this is the final step to deleting your pledge.
Note: If you are pledging to a per-creation creator, and they made a paid post before you delete your pledge, you will still be billed for that amount.