Thank you for the information and your question and I am sorry to read about your situation. You have a few options at this point. First, you might consider as a reliable first step (versus email), sending a certified letter to HR and copying the Company General Counsel (if they have one) listing your demands/concerns. You can let that know that pursuant to their policies (assuming there are written policies concerning expense reports and you have complied with your end of the policy) you are owed XX amount reimbursement for expenses and have not yet been paid. Secondly, you can reiterate your demand for your personal belongings to be returned to you. (They can require that you pick them up or they can mail them, under the law that would be their choice. They only need to make them available to you in some way that is reasonable.) You would then, in your letter, give them a reasonable deadline, perhaps a week to 10 days to provide payment and means of getting your items returned. Then you would merely let them know that if you do not hear from them within that time, you will exercise your legal options.
As far as your legal options go, they are to file a wage claim with the State for your expense reimbursement money( you can find more information and the form at the following link: https://www.illinois.gov/idol/FAQs/Pages/How-To-File-A-Claim.aspx), or to file suit in small claims court for both the expense reimbursement and the value of your personal items. Unfortunately, the small claims court does not have the authority to order the return of the items and can only give you the value. If you want a court order to have them returned, you would have to hire an attorney to file suit in District Court. If you do file either the claim or suit, you will need proof that they owe you the money. That would be by providing a copy of the policy and any documentation you have and your testimony. But again, I highly recommend that you take the first step with the certified letter before doing these latter steps. That way, if they do not respond, you at least can show the State and/or the Court that they received your demand and did not comply.
Please feel free to ask for clarification if needed. If none is needed, then if you could take a moment to leave a positive rating in the box above, I will receive credit for assisting you today. Thank you and Happy Holidays!