Tell them what? That googleadservices (saw that one on the bottom of my browser when loading the offending page) sometimes put Walmart ads on the page? Walmart’s answer would probably be “are people clicking through?” The point of targeted ads is for you to see companies you’re likely to do business with. Reload that page a dozen times you’ll probably get at least 1 ad for somebody you do business with (unless you don’t get any, every time I go I get nothing, turned off all my ad blocking and everything). The web ad business isn’t about direct relationships anymore. Anybody using these services has no control or concern with where their ads are showing up, they just want the clicks.
I might not care, but only to an extent. If something sufficiently reprehensible was being used by my ad vendor then it would eventually blow back on me.