The "Mute" and "Block" buttons are powerful tools for combating trolls and malcontents that infest every corner of the internet. So is the "log out" button on the website or app interface, and the power button on your device.
What's great about this is that circumventing mutes/blocks through the creation of different accounts is usually a violation of terms of service, either through rules banning sockpuppeting or targeted harassment. Reporting accounts guilty of this will usually result in sanction being taken, sometime up to and including an IP ban.
And of course, going around bans, logouts, and power-offs by pursuing others across multiple sites and even into meatspace can sometime be dealt with through the courts or law enforcement.
Or, if any of these measures are too severe for your taste, just move along.
And if everything fails, just roar in their face.