I helped my friend design it several times, but I just said it was difficult and didn't mention the money. This friend is my former boss, and now I don't work there.

If it were me, I would finish the task well and see his reaction, or just pay lip service. I have no choice but to say that I know this person very well. This person is not good Next time, if you insist on doing it for him, you have the right to be angry! This kind of person doesn't have to give him a good look. We can't make a good impression on everyone. Since he is so unkind, you should also refuse decisively, but this time you must do it, and don't say anything without paying. Come to you next time, spray him!