A debt shall not be understood to have been paid unless the thing or service in which the obligation consists has been completely delivered or rendered
When the existence of a debt is admitted by the debtor or established by the evidence of the creditor, the burden of proving extinguishment by payment dissolves upon the debtor who claims payment
In subrogation, the person who pays for the debtor is put into the shoes of the creditor
In reimbursement, the third person has merely the bare right to be refunded to the extent provided in the second paragraph of Article 1236 without the right to the guarantees and securities of the original obligation