If you are in the US, and do NOT have a contract that specifically states otherwise;

then all you are "entitled" to is at least the applicable minimum wage and, overtime....

nothing more... nothing less...

No, you can't...You can do this....Be thankful you even have a job....or quit....

Those are your choices....

I would ask if there were issues, why have they not discussed this before and left it until your review.

How can employees honestly expect to perform well if the management/supervisors do not highlight any weaknesses you may have ? Let you continue until you crash and burn ?

Be cautious here as if they have given you more work and have 30 days to 'improve' seems a bit unfair and are setting out to deliberately make you fail. You would be better to speak to HR or your supervisor as if the review was 'not true' as you state, raise a written grievance in line with the company policies and procedure.

Another example of poor management skills and blaming unsuspecting employees for less than expected performances and an excuse to fire.

You have absolutely no ground to stand on. Regardless of what you think you deserve, you are not entitled to anything in this world. Obviously, you have management that doesn't seem to think you are working hard enough. You are not entitled to a raise and you cannot sue a company because they don't give you one. If they fired you, you still don't have a case because you can get fired for any reason.

If you really feel that your review was unfair, read your company's policies regarding a review appeal, or in the least, write a letter to management stating that you feel you were given an unfair review and that you would like to schedule a time to discuss the merits of their bad review.

Stop trying to find a reason to sue someone and start worrying about what you can do to improve your performance at your job. You are obviously not performing to the standards they want. Go find out what exactly they want from you, or go find another job.

Where are you? Laws might differ in different countries. If you're in the US, they aren't doing anything illegal, and if they fire you, you have no basis for legal action - and they are NEVER required to give you a raise unless you have a contract saying they have to.