Your W-2 does not tell you how much your refund is. Your tax return tells you that. You do not automatically get back all the tax that was withheld.
If you are single with no dependents, under 65 years old, your only income is $30,000 on a W-2, and you take the standard deduction, your tax for 2016 would be $2,488. If you had less than that withheld, you would owe money.
You can look at your tax return and see how it arrives at a refund of $200.
If you have further questions, it would be helpful if you give exact amounts, and tell us what your filing status is and whether you have any dependents.
