need help with activation lock

my aunt brought her twin boys an iPhone around December 1st of last year the phone has never been turned on its mainly just for them to just play their games on. one of the twins has locked their phone so I tried to use iTunes with my computer to unlock it. but when I did that it immediately went to activation lock and now its is asking for someone else's icloud id and password. how is that possible and what should I do???????? THIS PHONE HAS NEVER BEEN USED OUTSIDE OF THE TWINS AND IT WAS BROUGHT OUT OF WALMART!!!!!! IT IS NOT STOLEN NOR SECOND HAND BOUGHT!!!!!! THANK YOU