rogers phones use sim card, you activate that not the phone, i don't know why or what your talking about an "15 digit S/A"
you can buy and activate a sim card at a rogers store for 15$
I have a rogers samsung used by my sister and idont know how to put the 15 digit S/A is, its not working!!! its a 16 digit with the space!! i'v tried 1000000millon times no joke.. HELP ACTIVATING IT!