can't activate sim/second line

[medievil]

I recently upgraded phones (moved my old sim to new phone no issues since my account is tied to sim).. later decided to add a second line with my old phone for my mother to use... ordered a new sim and no when I try to activate it, when I get to enter the phone IMEI, I get a prompt to order a new sim with no option to bypass....not sure how I should proceed absent calling an automated line that will not be able to do it either