Well, you don’t get an account action from someone else not liking you.
It sounds like you and your guild should probably take some time to have a read over this post from on of the Support Forum Agents:
It outlines exactly how ongoing harassment gets handled.
Based on your replies here, my guess is that your guild and these other groups are going back and forth and that the harassment is likely two-way. This will not end well for either side.
Put them on ignore. If they attempt to bypass ignore, open a ticket and report them for ongoing harassment. DO NOT reply to them at all. Nothing. Not even “Reported!”. Do not reply to them in any way. Everyone they’re harassing needs to do the same.
This isn’t about something being true or not. It’s about how to handle the situation. This forum is primarily for players like myself to help other players. It’s not a court of law or a one-on-one with Blizz.