You can file a compliant with the Equal Rights Division for the State of Wisconsin. Under existing law once you have made your request for your personnel records, the employer is required to provide it to you for a reasonable price within 7 business days. If they have not done this, then file a complaint with the ERD. They will investigate and if appropriate order the employer to turn it over to you. One caveat is that if the records are subject to legal action/litigation with which you are involved the employer may not have to turn it over to you.
In addition to filing a complaint with the Equal Rights Division, you may be pursuing a claim for unemployment benefits. If so, the employer must respond to the Department with a reason for your termination. That will answer one of the issues for you. If you or the employer appeal an initial determination on your unemployment benefits, you will have a hearing. You can ask the administrative law judge to order the employer to produce your personnel file for that proceeding. I think your most immediate way of getting your personnel file will be through a complaint to the Department detailing your request and the employer's failure to respond.