Hi there, TracyT!
Good for you that you got credits from your vendor. I wish I'd receive one before December ends.
Have you recorded the $20-credit already? If you haven’t, you can go to Vendors, select Enter Bills and click the small Credit radio button just above the Bill word. Enter the details of the credit and save the transaction.
When you pay your bills, select all three of them and click the Set Credits button to use the $20-credit you entered. Then, select it in the Discounts and Credits window, and click Done. That will do it.
Feel free to go back to this thread if you have other questions in mind.