Federal Perkins Loan servicer ignoring disability discharge, name change troubles

I won a total and permanent disability discharge in June 2020. Since then, my university has ignored it and continues to send me letters telling me I am severely delinquent on the federal Perkins loans I borrowed during my five years of attendance (Sept 2007-May 2012), and has just recently placed them in default.

I submitted scans of my total and permanent disability discharge letter, along with my court order of name change (the disability discharge was granted before my name change), to the servicer, in December 2021. I can view that scan on the servicer’s website (Heartland ECSI is managing them for my university). It has been seven months, and Heartland ECSI still says the Perkins loans are delinquent, my university has reported the loan status to credit agencies, and studentaid.gov reports that all the Perkins loans but one are in default.

All of these Perkins loans are listed on my TPD discharge letter as loans to be discharged, by the way. The same TPD discharge letter, that I submitted a scan of to Heartland ECSI, along with a scan of my court order of name change from July 2021, to show that I am indeed the same person entitled to discharge of those loans. Heartland ECSI updated my name no problem, and the website says my entitlement to discharge was “approved”, but their website also still says a payment of ~$4.5k is “due” on August 10th??

I have also had immense difficulty getting Nelnet to update my name, since I only changed my first and middle names, not my last name (my legal name change was part of my gender transition). Heartland ECSI uses my current name, and my university’s debt collection notices are all in my current name (both places updated my name without issue), but studentloans.gov as well as disabilitydischarge.com are under my old name. All of my student loans were taken out in my previous name, and my credit card is still in my old name (bc their process for non-marriage-related name changes is absolutely labyrinthine), but my social security card and state ID are in my current name. (My university is well aware of my name change, given that the debt collection notices are in my current name and they’re trying to collect a debt incurred under my old name. So I don’t think the problem is my TPD being in my old name.)

I am an SSI recipient in rural Connecticut with no savings and no ability to drive. How on earth do I fight it when a loan servicer completely ignores a disability discharge letter telling them “stop trying to collect these loans”?? And how do I track down a promissory note for a loan that was disbursed AFTER my graduation?