Rep Power: 0

A couple months ago, my Honda Civic 2012's odometer, trip display, and fuel range were disappearing and reappearing.

I paid a $200 diagnosis fee to Honda L, who told me I needed a gauge cluster replaced. They said they would not be able to fix it for two years because of a backorder on the part.
Honda E told me that they could get the part in two weeks, so I paid them $900 for the part and repair. This repair took place two weeks ago, and today my entire display when blank/white. Honda E claims I need to pay them for new diagnostics because it is a completely separate issue separate from them replacing it, and that it is the fault of Honda L.

In addition to the Honda E issue, I have also discovered that the repair was unnecessary in the first place because there is a Service Bulletin 13-017 that lists the exact issue and states all I needed as a $70 update/repair. I paid for services that I never needed in the first place, and the car is now no longer working. Both Honda dealerships are blaming each other, and I need advice as to how to proceed. Who owes me a refund, and who will be repairing the car that now has an even bigger issue?