Legal Question in Tax Law in Illinois

Best strategy: You can move on and prosper in a new environment. Question if you would have found your former employer's "underpaying and paying under the table" an affront to your sensibilities if your situation had worked out better for you. You can turn them in to IRS, DOL, IDES, IDOR, etc. but you will probably never know what happens with your complaint, especially if you cannot provide proof of a violation of the law.