Sounds crazy to me. I'm understanding that you never signed any contract, correct? If so, you are under no obligation to stay at a job. You are probably just an independent contractor anyhow. If you do have a contract, read it carefully for your answer.
My answer to you question does not constitute legal advice. Only an in person or telephone consultation will result in an attorney/client relationship. Call me at (313)402-0853 to discuss your matter further.
From the information you provided in your question, I would have a number of follow up questions before I would feel comfortable offering my thoughts. Generally speaking, employment in Michigan is at-will, which means you or your employer can end the employment relationship for any reason (assuming that reason is not unlawful, e.g., discrimination). However, if there is a signed contract, then additional rights or obligations may exist and need to be addressed. Also, it is not uncommon for employers to try and include contractual obligations buried within an employee manual that employees routinely sign at the beginning of the employment relationship. With this in mind, I'd recommend reviewing any documentation, manuals, etc. that you signed or were provided by your employer with the assistance of experienced legal counsel. Also, certain post-employment obligations may exist even if you did not sign an agreement, but this is much more difficult for an employer to establish, but something to consider (see the link below for more information on this point). I hope this helps.
I'm licensed to practice law in Michigan (www.shinnlegal.com). My response is provided only to educate the public about general issues that should be discussed with competent legal counsel in your state. Under no circumstances should you consider my response as a substitute for consulting an attorney in order to fully understand how the law may apply to your specific and unique circumstances.