That's not at all similar to what I experienced at IOP. Sorry that is happening to you! That they don't like your attitude pretty much sounds ridiculous, in my opinion. Freshly sober people don't tend to have stellar attitudes. As long as you aren't inciting others or combative, I don't really see it as any of their concern.
My IOP was for a 20 day intensive outpatient program... not 20 consecutive days, as we had weekends off. I showed up around 9am and left around noon. No lunch there. Just a couple short breaks for coffee. We were occasionally urine tested, but that's really the only rule or condition I can recall. It was a group of about 8-12 of us which fluctuated as people "graduated" the program and left, and as newbies arrived.
I am sure I received a list of rules in the welcome packet, but I really can't remember them. I must not have broken any.
But I do remember that any of us could walk away from there at any time if we wanted. There were no eating disordered patients (unless the eating disorder was a co-occurring and not the main issue). It was mostly young male drug addicts. I was in the minority actually, 30-something alcoholic female.