I'm here to share some information about transactions fees in QuickBooks Online (QBO), tyler-protean-gm.
Before anything else, I'd like to acknowledge the experience you shared with our customer service representative. This is not the kind of support we want you to experience. Let me make it up to you.
Your questions depends on how you processed the payments. If you're using QuickBooks Payments, there will be a charge fee every time you process a transaction. You can refer to the QuickBooks Payments website to check on the most up-to-date information.
If wish to avoid the fees in the future, you can just manually record the payments instead of using QuickBooks Payments.
Below are some handy articles that you might find helpful. These will guide you more about discount fees and what to do with rejected payments.
Let me know if you have further questions about invoice transaction fees or anything about QuickBooks. Have a good one.