Thanks for reaching out, you can use the "Report spam or abuse" option to report spam/abusive comments. You can find the detailed steps here: https://yt.be/help/dH3L . Hope this helps!
I shouldn't have to wait on YT to determine whether or not to stop this person. I should be able to block them and stop harassment immediately; a feature all other social media platforms out there have. The issue with trolls on YT is out of control. Please consider this feature.