Actually, if your mother's address was the one the insurer had on file for or in connection with you, they did the correct thing and sent the checks where they were supposed to. In that event, they are under no obligation to void the current checks and reissue them. Rather your recourse is to sue your mother for the checks: she has no legal right to hold onto your money and has to turn it over to you. If she will not do so voluntarily, a lawsuit is the way you force her to give you what is yours.