I Believe My Employer Is Breaking The Law

I am a full time, salaried employee in Indiana. My employer still requires that we work a set amount of hours or we could get kicked off salary and brought down to an hourly wage (our hours are dependent completely on the voluntary compliance of our clients). We have just shifted from a monthly billing period, to a two week billing period. Due to noncompliance, I have not hit my hourly requirements, as is the case for most people in my office. I suspected this would be an issue for my entire office, so when the owner came in to answer our questions during a meeting, I asked what would happen if we consistently don’t meet our hours. He completely ignored me and looked at his phone while I was speaking, then tried to laugh it off saying “I wasn’t listening”. I repeated my question and he had no answer. When I asked again at a later date they said they would deal with it on a “case by case basis”. Fast forward to NYE, I receive a paycheck that is about half of what I typically make. When I asked what happened, my manager stated that they dropped me from salary because I haven’t hit my hours. They didn’t provide any notice or even tell me how much hourly is before making this change, so it is a very unfortunate and unexpected hit right after Christmas. I have read that they are supposed to give me notice, however I also feel I’m being singled out as I’m not the only one in the office not hitting hours, but I believe I’m the only one experiencing this. Obviously based on their lack of answering my question, there isn’t a policy on this matter with this company. I’m not exactly sure what my next step should be. Any advice is welcome.