No one here can see your tax return, so it's impossible to give you a specific answer. Double-check your return for math errors. Or print last year's and this year's returns and compare them side-by-side. That can sometimes reveal an error (if there is one).
Tax refunds are strictly a function of taxes paid vs taxes owed. If there is no error in your tax return, you might want to adjust your withholding at work.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
