Car Dealer Question - Recall and Repair Issue

Recently I received a recall notice for my 2020 Honda Odyssey. It’s relatively young, less than 100k miles. We bought it used about 3 years ago. The recall notice we received was to repair or replace the SRS ECU module, which controls warnings for airbags.

After bringing it to the dealer for the recall, they upon review have stated that I will have to pay out of pocket for the ECU (about $2k). In addition, they found that someone had previously ran a resistor to the ECU, in order to supress the airbag warning light. They said that either it was previously wrecked and someone was covering it up to sell it to the dealer I bought it from (which, happened to be a TOYOTA dealer, not Honda), or some other funny business was happening. To fix that part, they are saying it would take an estimated $6k, and potentially another $1k if the airbags are no good.

I have debated with them back and forth that at minimum I should not be responsible for the ECU replacement, as it explicitly states it in the recall that they will repair or replace it. It hasn’t gone anywhere. I ended up opening a case with Honda Corporate, and a week and half out we haven’t gotten anywhere.

How would you move forward in this terrible situation?