Hi, I hold a TN-1 Visa through an Employer in Oregon. I signed and returned an offer letter with a different company. After receiving the offer I signed, the

Hi, I hold a TN-1 Visa through an Employer in Oregon. I signed and returned an offer letter with a different company. After receiving the offer I signed, the company called saying I'm ineligible to work in their data center, with their data, as a non-american citizen. They will not hire me. I have signed nothing further. (We signed the offer and worked on Visa transfer in parallel.) Do I have any options? What law prevented me from working?