I can add some insights about your invoice billing preference.
If you're subscribed to our QuickBooks Payments service, you have the ability to process both ACH and credit card payments. However, you have the ability to turn off credit card processing for a particular invoice before sending it to your customers.
You can do that by unchecking the credit card option on the Online payments section of the sales transaction. Please see screenshot below:
However, if you want to permanently turn off the credit card option, I'd recommend getting in touch with our QuickBooks Payments Support. They have the resources to check you account and help you with this preference.