i have worked for this company(huge fast food chain) only a few months, they have 1 employee who harrasses all new people and i had taken enough off her, she is pregnant and said she was gonna come back and hit me, the managers just let her run on and on, so i walked out. they in turn reduced my pay to min wage and also took out for insurance on my last check. my insurance was null as of day i quit. can they do all this and what should i do.

Despite what a number of people believe, pay decreases are not illegal. Under the law, the only thing any employer owes any employee (barring a bona fide, enforceable contract that guarantees a particular wage) is minimum wage.

In some states, an employee must receive advance warning of a pay decrease but I don't believe Ohio is one of them.

It is quite common, and quite legal, for an insurance policy to contain a provision that insurance ends on the last day of employment. If you elect COBRA, the coverage will be reinstated retroactive to the cancellation date, but they have no legal obligation to continue to cover you once you are no longer employed by them.

this is true, but they took out for the premium, isnt that my money if i am not covered any longer.

Not necessarily. The premium payment does not necessarily HAVE to be paying for time going forward. In many companies, the premium taken out on (for example) November 1, pays for your coverage during the last pay period of October. It does not always pay for the first pay period in November.