If the state is behind in processing their returns, they may not have gotten to your return yet.
According to the State of Illinois:
"We are taking additional steps to protect Illinois taxpayers from identity theft and fraud. To ensure the security and confidentiality of taxpayer information, we have initiated a review process to combat against fraudulently filed returns. As a result of the new security measures, refunds may take longer to process this year than in previous years."
(delays in tax payment processing may also be affected)