US VS Black MasterCard anniversary bonus miles

If you spend $25k in a year on the US VS Black MasterCard, you receive 15k bonus miles on your card anniversary (7.5k miles for a $15k spend).
I received a postcard informing me of my bonus last month (29 March), about a week after my card anniversary. But so far the bonus miles haven't posted.
My question is: who to contact to get this sorted, and how? After an initial attempt, VS says phone Bank of America, and BoA says phone VS.
I received a postcard informing me of my bonus last month (29 March), about a week after my card anniversary. But so far the bonus miles haven't posted.
My question is: who to contact to get this sorted, and how? After an initial attempt, VS says phone Bank of America, and BoA says phone VS.