Judge ignored deal with prosecutor? Sentencing, Plea Bargains

I got an MIP last year, and pled not guilty. at my pre-hearing i made a deal with the prosecutor for just fines and costs. he wanted to put me on the diversion program, but i said id rather just have an MIP on my record and not deal with all that. when called up i pled guilty, but the judge ignored the deal. ive done some research, and i found out judges dont have to respect those. but my problem is the judge actually said, "you have a deal for just fines and costs with the prosecutor?" and i said yes, and then she asked me how i plea and i said guilty. after i had plead guilty she said im gonna put you on the diversion program, and i said no, thats not what i decided with the prosecutor, and she said "well im going to put you on probation anyways so you might as well take it." is it legal for her to put me on probation after i had a deal for just fines and costs and had already plead? she didnt say she was rejecting the offer until after my plea.