Need some input...Help!

I'm very upset!
The day before yesterday I was searching in groups for my groups to be sure they were showing up. I typed in Rave Nation just as I always do and it pulled up a big list, but only mine are normally called Rave Nation on the title of the group or group member titles. Rave Nation is the name of my store and club and has been for over a year in SL with no problems.
I noticed, oddly enough that there was a new group that already had over 400 members and they are calling it Rave Nation. I'm assuming the club they are opening will be called this as well. I immediately IMed the owner of the group and told him the situation and asked if he would please change his group and club name since it was already taken and had been for over a year. The reply I got was:

[11:42] *********: just done a search for rave nation, mine's the only one that comes up!, yours appears under Rave Nation Club, sorry no can do, already got over 400 members, opening this week

I then tried explaining to him that the club part was not part of the name at all, I had put club on it to seperate it out from my other Rave Nation groups. To this he commented:

[11:56] ********: look lady, i've just about had it with you!!!! if you think i'm going to start a new group 3 day's before i open when i've got 400+ members you'r joking. do your worst


So, to be quite blunt, I'm very mad...and upset as well. I'm not sure what to do about this guy. There's no doubt in my mind that this will lead to confusion with people trying to find my store. I was not rude to him about any of it, but he immediately was rude with me...the two messages I posted here from him were his first two messages to me! I don't know why he's "had it with me." I was being nice! Now I think I've "had it with him" and I am trying to decide the direction I should go with it.
Has anyone had this problem? If so, what did you do? Does anyone know what can be done?

THIS IS TOTALLY LAME!

Sorry, you're outta luck. Group names aren't copyrighted.

it's not so much the group, but if the CLUB is going to be called R.N. also...my store and club are already called that..for over a year.
There must be something I can do about them taking and naming their club the same thing I did over a year ago...I hope

this might be a lame suggestion... you could start a new group and call it "Rave Nation Boutique" or whatever.... Group message your current Rave Nation group members, tell them about the change, then invite them all to the new group. Once they've all moved over, delete the old group to avoid confusion....