My FIA credit card closed two accounts - not just one --- is this legal?

I have two credit cards -- a FIA credit card and BofA card (I didn't know they were the same company). I called to dispute a rate change because one late payment (1st in a year - I have had the card ( formerly MBNA ) for 8 years) --- they ran my credit and decided to closed the account because my income does not meet their standards - now!, to which i agreed. However, I received two letters, one from FIA and one from B of A -- both indicated the same -- that the credit card account has been closed. The B of A card has not intro rate and I have had it for 3 years. While I agreed to the FIA closed account - I didn't for the B of A. Is it legal to closed the B of A account???