Every donation is processed individually. If you have already made your contribution and would like to adjust your Reward, please contact the project owner. If your preferred perk requires a higher contribution, the campaign owner may allow you to contribute the difference in Reward amounts and simply keep track of your preferred perk. In order to ensure you receive the correct Reward, please contact the campaign owner before trying to contribute the difference. [Related Forum Article: Contact the Project Owner]
If you have already made your contribution and simply wish to increase your contribution or select an additional Reward, you can do this in a separate contribution.
If you would like to check on the status of your existing perk, please see: How to Check on Your Rewards