Has anyone else struggled to leave the IRR? : Veterans

I was an officer (Army). I left the military with only a few months left on my IRR obligation. Shortly after ETS, I receive a letter in the mail stating that I have to officially resign and elect to leave the IRR. I returned the enclosed form (HQ AHRC Form 4145) signed and complete. I left a voice mail asking for confirmation but no one followed up with me. This was four months ago.

Fast forward to today, I get ANOTHER notice stating that I will be placed on the standby reserve list and be subject to mobilization by default if I do not respond. I called HRC who says I have to go through the IRR directly. I called the IRR branch chief and main customer service number. It goes straight to voice mail and no one ever returns my calls. I have left emails but no response yet.

Anyone have any advice what would get results effectively and stop wasting my time? Specifically who would I call or what would I do?

Update #1: After shaking some trees, a LTC emailed me with a form that I have never seen before and was not included in ANY of the mail I received. Any previous Army IRR officers see this before? I asked for clarification to confirm this is for IRR and not the regular reserves, as I already have an honorable discharge. The LTC claimed it will take about 8 weeks to process which I feel is them buying time and I will be in the same situation 8 weeks from now.