bien cumplido su cometido

I am not sure how to translate "teniéndose por bien cumplido su cometido"
below in blue my translation, in black the original text in spanish.

The referred Notary shall give the shares in its power against the delivery of the previously mentioned voucher from the Creditor, who is bound to return to the debtor when he requires. Once the shares are delivered, as per stated previously, the parties have nothing to claim the Notary for any concept, being his duty performed correctly, and who will be released of its capacity of depository.

El referido escribano deberá entregar las acciones depositadas en su poder contra la entrega por parte de LA ACREEDORA, del vale referido, el cual se obliga a restituir al DEUDOR cuando éste se lo solicite.- Entregadas las acciones en pago, conforme lo dicho precedentemente, las partes nada tendrán que reclamar al referido escribano por ningún concepto, teniéndose por bien cumplido su cometido, quien quedará liberado de su calidad de depositario.-

I would omit per and the verb release is followed by the preposition from

Best regards