Whose testimony prevails when an agent claims to have delivered the money and the depositary denies receiving it?

Primary text

If the agent claims, "I paid the money to the depositary," and the depositary replies, "You did not pay it," the statement of the agent must be accepted. This is because both parties are differing concerning the agent's execution of the mandate and the subject matter of the agency; therefore, the agent's word prevails in such a dispute.