When someone won’t stop making fun of you

What do you do when someone is constantly insulting and making fun of you, but every time you try to tell them how much they’re hurting your feelings, they say they don’t want to talk about it? I don’t want to force someone to have a conversation that is painful or uninteresting to them, but it’s also extremely frustrating to deal with constant insults and belittling, and have no way to express how hurt I am or make them stop.
First of all, telling someone to stop insulting and belittling you is not pushing them around. You have every right to tell them to stop, and telling them to stop isn’t bad, even if it makes them feel bad.
That said, it’s possible to tell someone to stop insulting you without making it into a conversation about your feelings. It’s ok to say “That’s not ok. Please don’t say things like that to me.” You don’t owe them a long explanation of *why* it’s not ok.
Sometimes it’s also good to end conversations if someone starts insulting you. Eg “I’m not going to stand here and be insulted. This conversation is over.” and then leave the room, or hang up, or whatever the ending would take in that conversation.