Kid still refusing bottle

Y’all I’m at my wits end. My son has been refusing a bottle now for a whole month! He has a nanny and she can’t get him to take a bottle , dad can’t and neither can mom. I BF when I get off work and weekends but I have a serious stock pile of breastmilk in the freezer now because he won’t take a bottle. I’ve got faster flow bottles I’ve bought dr brown bottles NOTHING WORKS.

Any recommendations or tips because this is beginning to work my last nerve