Can I sue my employer for failure to reimburse Moving expenses & sign on bounus offered in contract.

The position is in Dallas Texas the headquarters of company is in Illinois.
I recently accepted a new job in Dallas Texas. I moved from Jackson MS. In the final offer letter extended, they offered moving reimbursement, repayment for breaking lease to move, and a sign on bonus. The offer letter also outlined my position, salary, and company reimbursement for continuing education credit. I accepted the job and moved to Dallas and start date was 7/31/17. It was outlined that I would receive my moving reimbursement by 9/15/17 when they issued reimbursement checks for the entire company for mileage and I would receive my sign on bonus after 60 days with the company. I will have been with the company for 90 days on 10/31. I have yet to receive my reimbursement or sign on bonus. Each time I inquire I receive a different or altered response: I was told they mailed it (never received it) and that they had issued a stop payment on the check, I was told that it would be direct deposited into my account on 10/15/17 since they were out sourcing their payroll to ADP, then when I did not receive it I inquired ans they said they would mail it on 10/20/17 ( received payroll check but not the additional funds owed). When I try to call payroll they do not answer. When I've emailed the operations manager/hr department they have not responded to my emails. I got another email from the payroll manager saying he was mailing it on 10/23/17 but I still have not received it. Do they have to honor the offer letter that is signed and I have all the