Under the Bullard-Plawecki Act you have a right to your employee file. Document you request for the file, to prove that you requested it, as you have done. Regarding you rights, that depends upon the nature of your working agreement. Do you have a contract? In Michigan most employers are prudent enough now to generate documentation that your employment is "AT-WILL". In other words, you can quit if you want, and they can fire you if they want. So check your contract, if any, and your Employee Handbook. If you are an "at will" employee, an employer has no obligation to give you a written explanation as to why you were fired.