I understand your issues, it seems this is happening all over on multiple planets, Big groups, or even small groups whom have a lot of money to spend/time to play.
As it was stated before-- Report the name in game, And wait. If you have done nothing wrong you will be fine-- we are in the same situation with our town. Devs have stated they are working on something-- they can’t say what-- but are working on something to try and fix this issue.
For now, your group can either wait patiently, pack up and move elsewhere/another planet, or other.
We are option to wait for what a Developer says as we reported the player for what they did to us. Based on what the dev states will determine if we play where we are, move, or other.
It’s not a small issue, a lot of people are increasingly doing this, to take over and gain control, grow their own cities, or are trolling. But because as many told me-- it’s the name of the game: turf wars-- You either fight back, or give in. And the only legit way to fight back, is building prestige for naming rights. Keeping active members is important.
I will watch the thread to see if your group gets any differently from our situation, and wish you and your friends all the best!