Reason they did not acknowledge my amended return. What do you mean by acknowledge? it could mean they never got it or got it and but not accepting the changes because the required documentation was not included. if you are unsure, that notice you got should have a phone number. call. it should also state what steps you can take if you disagree with its findings.
here's a link for ways to contact it
https://tax.illinois.gov/aboutidor/contactus.html