This isn't the kind of experience we want you to have while processing customers' payments in QuickBooks, @Shotgun73. With this, I'm here to guide you on the actions you need to help take care of this matter.

Since the Community is a public forum, and we'll need to collect some personal information to pull up your account, I'd recommend contacting our Customer Care team. They can securely check why customers' credit card and money in transactions keeps getting cancelled and guide you with a fix.

You can refer to this article for the step-by-step guide: Contact Payments or Point of Sale Support. Please choose your product (i.e., QuickBooks Online with Payments & Merchant Service Center or QuickBooks Desktop with Payments) so you can have the appropriate steps.

In keeping with this, I'm also adding this article to answer the most frequently asked questions about processing payments in QuickBooks:  FAQs for QuickBooks Payments. It includes topics about funding status, managing accounts, and payments processing, to name a few.

Please keep me posted on how it goes. If there's anything else that I can help you with about processing customers' credit card transactions in QuickBooks, let me know in the comment section below. I'll gladly help. Take care always, @Shotgun73.