You just need to contact MS (I can't remember whether chat or email will work or it has to be via phone), give them the two confirmation numbers, and ask them to please merge them into a single reservation. That's assuming they're exactly the same villa size and type (and view, if BCV had views). If they're different in any way - lockoff 2 BR vs. dedicated - then ask them to link them as a "continuing stay." Obviously, if they're different you'll have to move, but maybe they'll be able to get the new room ready early enough to facilitate the move.