New Dues???

I am so confused! Here's the deal, and I need some advice. My sorority is seriously lacking in numbers. I pledged last semester. I was told that I did not have to live in the house, because I have a lease from prior to pledging. I was told it was OK, there would be no problem with that. I was also told dues stay relatively the same every year, there would be no hidden costs, etc. And again, no problem, I can live wherever I want.
The day after initiation, the president told the girls who had just been intitated(me too)that if we didn;t live in the house, we were going to have to pay some extra dues, because our numbers are so low. So, we think, like, 50-100 bucks, no big problem. Well, my dues TRIPLED!!!!
Our school only has about 6% Greek, so it's hard to keep our numbers up, but we're low, even for my school. It's so bad, national is threatening to close us down. Needless to say, making mortgage payments on the house is not going to be easy. But I feel like I was lied to, because they need anyone they can get, just so they can stay open. I don't feel at all sisterly, and I'm pretty pissed off.
I already paid the dues, and that really isn't my issue. Is this common practice? I am a new member, maybe I just don't know the ropes yet, but it still doesn't feel right. I joined a sorority to make some new friends and hang out with some cool trustworthy people. I feel like I got the shaft, and was really lied to. Let me know what everyone thinks.