When you get a chargeback in QuickBooks Online, you'll receive an email notifying you of it. Within this email should be instructions on how to handle the chargeback. We also include the case number, email address, fax number, and how to send your response in the email we send to you.
If you don't see this email, be sure to check your junk/spam folder.
However, if you still don't notice any instructions on how to handle the chargeback, you can use the link I've included below to in touch with our Payments Team.