This post (and the numerous suggestions from the community in the comments) might help! https://food52.com/blog...
Vinegar can be tough. You can't balance it with something else. Dilution (suggested in the blog post) makes sense. You'll want to increase the volume of whatever you're using in the chili recipe. Bland beans or whatever meat you're using and many more tomatoes comes to mind. Possibly something as simple as tomato paste diluted with some appropriate liquid may help.
Glad to see people aren't suggesting adding sugar, which would tend to bring it out more. Longer cooking could help.
Depending on what type of dish it is, if the flavor is too acidic because of too much vinegar, adding a very small amount of baking soda can help neutralize it to make it less harsh. This works well for dishes like soups, stews are braises where the baking soda can really be incorporated. I'd start with about 1/4 teaspoon, and then gradually add more if needed.