Suppose that an international grad student at one of the University of California campuses got an offer letter:
Congratulations! On behalf of the Committee on Admissions and Awards and the Graduate Group in (Department name), I am pleased to offer you the following financial support for the upcoming 4 years. The funding will be in the form of a Graduate Student Researcher, Fellowship and Teaching Assistant...The details of your award are as follows:
Summer Support with Professor X (3 months at $5000.00 per month) $15,000.00
But the student's first summer paycheck amount is only around $4000 (before tax). An email to the professor got an answer saying "The pay check amount is true. Sorry, there is no more fund available for you at the moment!"
Can a professor behave like this? Why the offer letter of the university with the signature of the Department chairman below it, specifies some amount of money but the pay check is in different amount? Is such a thing legal? If not, what is the appropriate 1st step to remedy it?