Dishonest

I purchased a Samsung J1 in about June 2016. I only used the phone for calls until Xmas. My young nephew helped me set up my email on the phone.. But said hey! there is already someone's email address in the phone. Then looked to Google search and found the repair centre. Game had sold ne a 2nd hand phone. I took it back to the store who recalled me and said they had taken it from a sealed box. The manager assure me he would get to the bottom of this. A week later I was offered a FULL REFUND and said that they refurbish phones and sell them as new phone. If not, why was my phone taken from a sealed box.