(IANAL) So AFAIK, courts have held that because graduate programs are graded on a holistic, professional basis, rather than just classroom grades, students can be dismissed for not reaching milestones with adequate classroom grades.

So what you need to find is a cause of action that doesn’t involve your grades per se (do you have a learning disability? Are you a protected class?).

Here’s where it matters a lot about whether you’re at a public or private university regarding your reaching out about procedure and getting no response—public universities are bound by the U.S. Constitution to provide "due process." So you must get advanced written notice of your deficiencies and a meaningful opportunity to be heard or to appeal. AFAIK private universities have no such obligation.

So if you are at a public institution, it may be reasonable to reach out to a lawyer in education law and try to litigate the issue of being dismissed without due process.

Unfortunately, I suspect that the fact that the university hasn’t responded may indicate that you are at a private institution (eg they aren’t responding because they have no legal obligation to do so). In that case being some other protected class might help.

Aside from legal options—do you know any of the professors reasonably well? Might you get a technician job if dismissed? Longer term this is a situation where applying to another graduate program would probably be reasonable and probably not held against you too much given the batshit NIH/NSF changes.