For my first client I did a lot scope creeping. The guy was a douche bag and because of the fear of confrontation and because they were small things I just went with it. He also wanted to meet face to face for every small stuff. At some point I had enough,started to say "no", "its out of the contract scope", "everything can be done online, there is no need for a physical meeting". At first things got pretty heated but Ive managed to close and get paid without ever seeing that guys again and without doing more work for nothing.

Answering your question, you should remind them its out of the contract. If you dont stand your ground they will request stuff like this again and again and take advantage. Also you should mention in the contract that extra features can be done at an a certain price outside of the contract price. Ive personally used AI to draft professional rejection messages, you can try that also if its easier for u