I have question regarding my job?

Since, Oct. 26 we have been under this new umbrella and they have changed many policies and decided to give us a orientation today after how many months later of changing its name. Explaining to us that I'm now a part time employee because I make less then 40 hrs a wk. I no longer get paid holidays or get benefits. Reason being is part time employees do not get this. I have been working for the previous companies name for almost 4 years. Now, I have to work a 6 mth probation period w. the company all over again. Is this legal? The handbook they gave was in-accurate and misleading. They also said it had typos? If they knew that,then why go out of their way to get a meeting together and all before the long holidays. This is so unfair and I'm so upset. Pls..need advice. Thanks.