Can a hospital enforce a policy they have to restrict former employees from coming back as a vendor for a certain amount of time? Not a non compete because nothing was signed it was just a policy added and was supposedly verbally told to all employees. Al

I accepted a job with a company and my prime responsibility was to be taking care of a certain surgeon at the hospital I currently work. I searched the employee handbook and everywhere for any reason I couldn't take the position. After turning in my notice I get told there may be an issue and I could not come back here for a year because of s policy I have never heard or seen. HR produced a written copy of the policy which they say was implemented in 2005 but when I asked did I acknowledge it and say I had never seen or heard of it to which my boss tells me and the HR rep he hasn't ever seen it either. I emailed the COO to ask for it to be waived to which she declined saying there r several employees who have had to wait but I know of 3 I have spoke to that said they did not. This is not even a corporate wide policy it is simply a hospital policy they say was put into place to keep vendors from cherry picking the best staff away. This job was a significant raise for me and my family and a huge opportunity. I don't want the hospital to fire me for arguing this but if I can't come here to my hospital then they won't consider me for the job. What am I to do? I even asked the HR guy if they could produce something signed showing my receipt of the policy and that I agreed to it to where he said it was ten years ago and they couldn't do that. Then he "warned" me about keeping up questioning this and I felt like it was a threat. HELP ME PLEASE