Since you have tried obtaining his discharge papers and were given a response. If you still want his discharge papers I would contact your fathers state veterans office, county veterans service office, and or county recorders office. Many states offered a war stippeded and other benefits requiring service member to file paperwork. I found my fathers this way. I would suggest trying this route.
Dear Mr. Wilhelm,
Thank you for posting your request on History Hub!
The medical records of the 158th Regimental Combat Team would not contain information about the injuries of an individual. We would suggest, however, that you request an individual medical report for your father and morning reports for his unit.
Individual medical reports of veterans who left the Army prior to October 16, 1992 are in the custody of NARA's National Personnel Records Center in St. Louis. Please complete a NA Form 13042 and mail it to the National Personnel Records Center, (Military Personnel Records), 1 Archives Drive, St. Louis, MO 63138-1002.
Due to the coronavirus public health emergency, the National Personnel Records Center is servicing only urgent requests related to homeless veterans, medical emergencies, and funerals which may be faxed to 314-801-0764. We thank you for your patience and look forward to resuming normal operations when the public health emergency has ended.
Morning reports for Army units (from November 1, 1912 to 1959) and Air Force units (from September 1947 to June 30, 1966) are in the custody of the National Archives at St. Louis (RL-SL). For access to these records, please contact RL-SL via email at email@example.com.
Please note that due to the COVID-19 pandemic and pursuant to guidance received from the Office of Management and Budget (OMB), NARA has adjusted its normal operations to balance the need of completing its mission-critical work while also adhering to the recommended social distancing for the safety of NARA staff. As a result of this re-prioritization of activities, you may experience a delay in receiving an initial acknowledgement as well as a substantive response to your reference request from RL-SL. We apologize for this inconvenience and appreciate your understanding and patience.
We hope this information is helpful. Best of luck with your family research!