[UPDATE/ADVICE NEEDED] cutting ties with toxic parents?

I recently posted about my situation on here regarding my toxic parents.

TL;DR Physically abused by mom from grades 1–10 for not doing well in school; mom arrested; foster care; parents awarded custody and sent to anger management classes cause they hired a good lawyer. Abuse continued and got worse. Dad and mom were verbally and emotionally abusive into adulthood. Moved out at 25, wrote letter and emailed it to them stating NC and outlined abuse. No contact since.

So, I posted recently I didn’t hear back from my parents since having wrote the letter, which was early June. Sister had reached out, seemed to be neutral, but when she found out I got a new phone number, was immediately pissed by the fact that I wouldn’t give it to her and said that me not doing so was hurtful. The entire family has never addressed the abuse.

I am reaching out because I just received a letter from which it seems my dad wrote as the language and the way things are worded is very much like how my dad talks. Nothing was addressed and all that was stated was them putting all the blame on me. He outlined how they “did everything they could for me” and how they “tried to fix me”. He doesn’t apologize for anything and instead states that I was the one who “couldn’t live up to their end of the expectations”. One point he made was that my sister went down the path they wanted and how I “failed to follow down the same path”. He doesn’t even mention or acknowledge that abuse occurred and spent an entire page and a half making me out to be the one who did them wrong. That basically because they provided for me and because I didn’t live up to their academic expectations…I was the one who is in the wrong, not them. It appears they were trying to justify the abuse without actually addressing it ever happened or implying that it wasn’t wrong for it to have occured.

I need all the advice, thoughts, and support I can get. Am I in the right to burn the bridge completely?