the REF letter usually sends to both you and your atterney.
Same thing happened to me before, it is a bit complicated for me. we moved to a new house month earlier, my company also changed immigration law firm month earlier. I did do change of address from USCIS website, but company had not gotten a chance to file change of attorney yet, because I was years away from being current. After 2.5 weeks not receiving it, I contact my HR dept, and HR manager contacted both old law firm and new law firm, luckily the old firm did receive it and they overnight fedex to me, it was about my son turn 14 and he needs new FP.
