Graduate school making me pay for health insurance post graduation

Location: Tennessee (TN), United States

I finished my PhD with a university in TN in September 2024. I had been employed by the university as a research assistant during the PhD and was receiving health insurance from the university via a United Healthcare plan. I ceased my affiliation with the University on Sep 30 and stopped receiving paychecks from them on that date.

Recently, I learned that I had a pending charge for health insurance coverage, more than $2,000 for coverage for the current semester. I am not and will not be part of the university in any way for the semester that they're charging me insurance for.

I filed a request for a "waiver" with the University's student health insurance committee and they rejected me, stating I had missed the waiver period which occurred during the month of December 2024. During the waiver period they sent emails to my university email account stating that I needed to request a waiver or they would re-enroll me in insurance for the next semester. I was not employed by the university and had in fact found another job by that point.

This all feels totally absurd. I ceased my affiliation with the university in September. Months later they buy insurance for me because I didn't respond to emails on an account associated with a job I no longer had. I find it insane that the university could buy me an insurance policy that I don't want or need after I'm not affiliated with them, then claim that it's my fault and I have to pay for it.

How should I respond? Would an employment lawyer be any assistance? Would it cost more in legal fees than just sucking it up and paying these bureaucratic assholes?