I think I tried lecturing a site mod once, I'm sorry for that, please help

so an alt has been harassing one of my friends for a while now. We banned them streams and blocked the alt, but whoever it is guessed my friends password, and un-banned and un-blocked themselves. I don't know what we can do at this point. https://imgflip.com/i/5ycwon?nerp=1639865039#com16165463