Charitable Contributions Not Recording Properly In Quickbooks Desktop

We use Quickbooks Desktop. We donate non-inventory product to charity. We have a Charitable Contributions expense account set up. We put the donated product in the Item List as an Non-Inventory Part, our cost in the Price, and the Account as Charitable Contributions. We prepare an invoice for the applicable Charity for the donation. After the invoice is prepared and saved the donation shows as negative amount in the Charitable Contributions expense account. We prepare a Credit Memo to apply to the invoice which zeros out the invoice as zero amount due and shows the invoice as paid. The Credit Memo also applies the credit amount as a positive amount in Charitable Contributions expense account which zeros out the initial negative amount from when the invoice was prepared, thus leaving a zero amount as contribution in the Charitable expense account. We cannot figure out why the amount in the Charitable expense account ends up as a zero contribution. Is there something we are doing wrong or didn't set up correctly? Would there be a tie-in of our product with Cost of Goods Sold? We have reviewed the steps for contributions and setting up the expense account, adding item to the item list, doing the invoice and credit memo found in other postings but cannot find a solution.