Dear sherryfrey

Welcome to this forum.
From what you describe is a very delicate matter between your boyfriend and his mother.
Is obvious a fraud action from her to get credit cards in his name. But also are responsible banks that issued cards to a woman in a man's name.
He has to contact with issuers to inform them that never send aplications or if they have such aplications to issue credit cards are fake. Then the problem will pass to them to find the truth.
In such case his mom will be soon to jail for fraud actions repeatedly.
I hope that gave you some ideas to your problem or else you have no other choise but to walk alone