I'm so sorry that your chapter is going through this...
The same thing happened to my chapter a few years ago. We are the oldest house on campus and all the PMN's wanted to be part of the new houses. Along with COB'ing, we realized we needed to make Sigma Delta Tau a more recognized name. We decided to hold a huge philanthropy event that involved pretty much everyone on campus. It was a "Mr./Ms. University" Pagent. A representative from each GLO, ROTC, sports teams, clubs, etc would participate in a "beauty" pagent. We hung up pictures of the contestants all over campus and allowed people to vote for their favorite person for $0.50 a vote. On pagent night, the group was narrowed down to the top 10 from the campus-wide vote. Then, after a talent portion and the eveningwear competition, the winner is selected by the judges. The event was HUGE!!! Our first year we raised $15,000 (half goes to SDT's philanthropy, 25% to the charity of the winners choice, 15% to the charity of the 1st runner up, and 10% for the winner to keep). All of a sudden, everyone on campus was talking about SDT (in a positive light!!!) and women were interested in rushing us! After 3 years, our numbers are as good as everyone elses.
I hope you guys could do something like this to help get your name out. And I hope you have the same happy ending that we had!!!!!!!!