Customer paid invoice with credit card, payment posted. 2 days later payment was taken from me and customers invoice total is written in red. What's going on here?

Welcome to the Community, Reliablesafetysv.

When a credit card payment is rejected, QuickBooks usually sends an email about why it was declined. If you didn't receive any mail in your inbox, I suggest contacting Payments support. They have the necessary tools to review your concerns further. They'll also guide you on how to fix this issue.

Here's how to reach Payments support through QuickBooks Online:

1. Click Help (?) at the top right.
2. Select or type Contact Us.
3. Enter a brief description of your concern, then click Let's talk.
4. Choose to Ask the community or Start a chat to connect with us.

You can reach them from Mondays through Fridays, 6:00 AM to 6:00 PM, Pacific Time Zone.

Check this article out to review commonly asked Payments questions: QuickBooks Payments FAQ.

In case you want a summary of your customers' payments, here's an article on customizing reports to get it: Customize reports in QuickBooks Online.

Please don't hesitate to reach out if you have any other questions about receiving your customers' credit card payments. I'll be around to help you out. Keep safe!