Good morning, @melissa-pennflee.
Congrats on making your first post here in the Community. I can share some helpful tips to get this situation taken care of with reconciled vendor credits that need to be voided.
If you void or delete these vendor credits, that have already been reconciled, it will mess with your reconciliation.
In this case, I suggest consulting with your accountant to be sure of what steps to take in order to resolve the problem. They'll be able to give you the best advice based on your business.
Keep us updated on how the process goes. I'm only a post away if you have any other questions. Have a great day!
IMO, the best way to clear them is to create bills using the same accounts from the credits and then paying those bills with the outstanding credits. This will clear the credits and the bills and credits will offset each other. Also, this will leave a better audit log in case anyone ever needs to track it. You can enter "to clear credits" as the bill number and make a note of why the bills are being entered in the memo field.