Tuition Reimbursement

I had to payback to my old company the Tuition Reimbursement. It was a significant amount and almost 30% higher than the reimbursement due to taxes and etc.  The w2C i received only corrected federal in boxes 3,4,5,6.  It did not correct wages. Do i need to ask my company to correct the wages and state taxes too? It is over 40% of my actual wages. Or do I back into the wages manually?  I do not qualify for the tax deduction for grad school.