if you have activated a new card this means you have a new account.... as you can only have one sim per account..... so, you need to log back into your original account and do a sim swap.....
This great guide will help you out . . . . .Order a free SIM
A sim swap usually takes a few minutes to complete . . . . remember restart phone after the stated time . . if you need any other help please come back an let us Know here .