I am an existing Disney plus customer, paying monthly supscription. I tried to redeem the free 3 months code sent by Samsung, but in Disney account it says you are already customer.
I don't use that service. But maybe you can wait till your current subscription runs out, and then try it again. Maybe you have to change your payment option as well. I don't know. Try to contact Samsung support or maybe even contact the Disney+ service support.
