Thanks for the follow-up, @Nancy S.
I'm here to help route you to our chat specialist who can handle this in a remote session.
Ideally, the vendor credit should show on the bill payment stub if it's applied on the bill payment transaction. I also find this unusual since you don't have any credits on the screenshot you provided.
This case should be thoroughly checked by our QuickBooks Desktop Customer Support. They can help using their necessary tools in a secure environment and provide you further with the appropriate resolution.
I'm sure this will be taken care of. Let me know if you need anything else or if you have other questions about your bill payment stub. I'll be here to help however I can.