What do I do about negative comments on my ads?

You can delete them and then set a rule moving forward to block certain words and profanity from your page.

How to Block Words:

Step 1: On your Facebook page, Click “Settings.”
Step 2: Go to “General” then “Page Moderation” Click “Edit.”
Step 3: Type in the words you want to block or upload a .csv file containing the words you want to block and click “Save Changes.”