If formal it is best to avoid contractions such as we're or don't, shouldn't... etc. From the wording of this message I get the sense of formality so I will correct it as if it were a formal reply. We are glad we could be of service/assistance. Thank you for entrusting us to perform the tasks you required. Please do not hesitate to contact us if there is anything else we can help you with. Has hecho un buen trabajo :)