I'd love to direct you to the best help available so this gets taken care of, @Cstpeter7.

Since your setup is correct, I recommend contacting our technical support once more. One of our experts can pull up your account to check everything up and find more solutions. They can also escalate this issue if necessary.

Before that, check out our support hours. This way, you can connect with us quickly and at a time convenient to you. Then, follow the instructions below:

1. Log in to your QuickBooks Online account.
2. Select the Help (?) menu.
3. In the Assistant window, type in “Talk to a human” in the field.
4. Enter “Credit Card payment option keeps failing to be added to my client's email invoices,” then go to the Contact option.
5. Choose a way to connect with us:
   • Start a chat with a support expert.
   • Get a callback from the next available expert.

If you'd like to add specific information to your invoices, check out this article for complete instructions: Customize invoices, estimates, and sales receipts in QuickBooks Online.

Moreover, QuickBooks offers ways to create a template for regular transactions and make customers' payments organized and connected from start to finish. For more details, see these resources:

• Create recurring transactions in QuickBooks Online
• Set up and send progress invoices in QuickBooks Online

Don’t hesitate to leave a message if you have any other questions or concerns besides the credit card payment option. I’ll be here to help. Take care!