Hi Rock
If you went to court on this, you would have no chance. You voluntarily terminated a tracker mortgage and took out a new mortgage.
However, I have seen a case where AIB contacted someone in a similar situation and put them back on the tracker, as part of the Central Bank review. There was no legal obligation. I don't think that there was even a moral obligation. But they decided to do so.
It may be that the Central Bank is pressurising the banks to do this. I just don't know. Bank of Ireland would probably resist such pressure, but if there aren't too many cases, they might just concede it to keep their energy for bigger battles.
So don't do anything like switching to another lender. Write to Bank of Ireland and ask them to confirm that you are in the review.
In the meantime you might consider fixing with them for one year to reduce the rate you are paying.
Brendan