Can I sue the department or university? Even if there is a clear evidence of confusion, the department is doing wrong.

I want to sue my university. Even if there is a confusion between the department and graduate school and the department misinformed the policy, the department is suggesting me to graduate with master degree due to graduate school policy. I think this is unfair to student and they ignored my time and money I spent so far. I have a clear evidence of confusion (emails from the department)