Verb conjugation of "cushion" in English

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.
Was that all? I was sure that I had a lot more mistakes, because I did not know how to express myself properly. Maybe I am a natural born talent. I am just kidding. Let me know if you need something else.
I really would like to invest more time here but until now I was too busy to keep my promises. Maybe I should take a vacation and go back to Scotland and take another language course there.