Can I pay off past due Game Pass charge with my account balance or with a prepaid card?

You can't use prepaid game card to pay a past due balance.

If you have a past due balance, you have to pay off the balance you owe first with a credit card/Paypal. You won't be able to use a prepaid subscription card until the balance is paid off.

Overdue balances can only be paid with credit card or Paypal. You will not be able to use a prepaid card until the balance is paid off.

if you used Gold or Game Pass or Game Pass Ultimate after the expiry date and recurring billing was turned on but there wasn't enough in your account to pay for it, it would get a Past Due Balance on the account.

this Past Due Balance has to be cleared before any other purchases can be made with that account.

the following link has all the details on how you can pay the balance off

https://beta.support.xbox.com/help/...s/pay-past-due-balance-to-unlock-subscription

Unfortunately, you can't use your account balance to pay for a past due amount.

You will have to
go to this page here to pay your past due amount of money, and use your bank account or credit card with sufficient funds.

After you payed your past due amount, you can then redeem your 3 month card again. You can't redeem any prepaid codes with a past due amount on your account.