Handling Vendor Credits

Typically vendor credits are issued when you return an item or successfully disputed a vendor charge that has cleared the bank and has been recorded in QuickBooks. The process is handled based on whether you have arranged for a reimbursement or agreed that the credit be held on the church account with the vendor. If given the option by the vendor, you should specify that they should issue a reimbursement. 

Additional situations are explained on the QuickBooks support page Enter vendor credits and refunds in QuickBooks Online.