I'm no dev but let's say that my job has a similar issue. The approach that I use focuses on being 1) truthful, 2) clear, 3) polite, 4) concise. In this specifi

I'm no dev but let's say that my job has a similar issue. The approach that I use focuses on being 1) truthful, 2) clear, 3) polite, 4) concise. In this specific order. In other words: "Sorry, I'm not going to do this because [insert here the actual reason, not some lame excuse]". Past that, if that user keeps insisting, the user is being entitled and you should not bother yourself with entitled people.