How is a dispute settled when the total amount paid exceeds the actual debt owed, and the parties disagree on the division of the surplus?

Primary text

If the amount paid exceeds what was actually owed, and the parties disagree on the division of that excess, the claim of the party asserting equal division prevails. This is due to their joint payment of the amount, granting them joint custody over the excess, similar to a situation where they jointly possess property and disagree over its division.