Translation of Kameramann

The billing of additional working hours is not justified, since it was our request to download the software and wait for the new version. They have admitted the error of the translation.
I have sent you the translation a few hours ago. I guess it has just arrived. That is very responsible of you. I will have a look at it immediately. If you want to address somebody formally in the singular, you must use 'usted'.
My company is a consulting firm for IT systems for banks and insurance companies. I work with system analysers and bank employees. It is a big challenge, technically and commercially. I love it.