Thanks for reaching out. If you believe any ad that violates our terms of service, please report by flagging it: https://goo.gl/5dz2tC . Also, you can manage your ad recommendations, here's how: https://goo.gl/k5Wv7X . Hope this helps.
Thanks for bringing this to our notice. We rely on YouTube community members to flag ads that they believe violate advertisement guidelines. Also, any chance you have the URL for the ad's landing page to help locate this specific ad? Keep us posted.