How do I treat a credit that is carried over to the next CC statement

We are a small animal rescue using QB Nonprofit

We have 2 checking accounts.  One for General Expenses and the second for Grants.

All our bills are entered based on which checking account is used i.e. Accounts Payable or Grants Payable.

We have been given a grant for spay/neuter for cats and dogs in our city, as well as our cats as well.  Included in the grant is a $25 copay for cats and $75 copay for dogs from the public.

We work with 4 different vets in our area to fulfill this grant.  3 of the 4 will deduct the copayment from the total fee and bill me the balance.  One vet (who is also our regular vet), will credit me the copayment, then when the pet is spay/neutered, charge me the full amount.  This way, for simplification purposes, everything is under our account, instead of new accounts for each person.  In the end, it all evens out, but it can get confusing with the billing.

The vet bills me weekly.  At the end of the last CC billing cycle, I received a set of bills.  The total of the bills was $355.70.  All of these expenses were general medical expenses, under Accounts Payable.  It also included a cat copayment of $25.00, showing as a credit of $25 under Grants Payable.  Unfortunately, there were no grant expenses to credit it against.  The vet billed me at $330.70, since the $25 was deducted from the bill.

So now I have a bill that does not coincide with my books.  I also have a $25 credit carried over to next month under the Grants Payable account.

How do I reconcile the CC account?