PhD Dismissal after 6 years, how do I fight for it?

After COVID, I came back and continued to work in my full-time teaching job while requesting the faculty advisors to revisit my coursework. But they were adamant that I take the missing coursework. They realized about the missing coursework when I applied for graduation when I am ready for defending the thesis. Like I mentioned, I was stuck in my home country without pay for 7 months, I came back to the US with a debt and I do not have the means to pay for the extra coursework they assigned. So, I requested them for reconsideration or financial assistance. It was unsuccessful. After several unsuccessful attempts, I reached out to the dean mentioning my situation recently, and asked for an opportunity to complete oral defense. And last week I received a dismissal letter.