Advanced Call Forwarding disabled, can't setup NomoRobo

I am unable to enter the NomoRobo number in Advanced Call Forwarding. Instead, I see the message "This telephone number does not have access to Advanced Call Forwarding". I have attempted to resolve this with 4 chat agents, including one callback. No resolution. I am the primary user on the account, and therefore I have no option to toggle it on/off. Please help.