Looking for a random pic for work I typed "img" on DuckDuckGo and child pornography appeared.
I sent an email to report the crap, but no reply back.
What should I do more?

Pretty sure that if someone read that they will put everything in motion to remove the images.

But you could also contact the police. So they might find the owner of the content and put them away for a long long time.

I accidentally votes up, no option to change it :(

Call FBI

Most countries have a government agency, where you can report such things. Probably they have better luck reaching a responsable person.

Another thing you could try, if they have a bug bounty or similar program, report it through that one, then it should go directly to someone who knows their shit instead of some first level suport person.