Unbelievable what happened to me as an intern

I got a traineeship in an office, but unfortunately I didn't reckon with this lousy head of department who thinks he can do anything, he's probably known for being a nasty guy! I must have made a few minor mistakes while working with Word, but maybe he did it himself to accuse me of making a mistake, I've only been doing this for a short time, I don't know, but in any case I didn't expect so much malice.