What does BB do with a broke PS3? Need Help

[ThereWillBeBud]

Sorry if this isn't quite the right forum. My ps3 died in April and I took it to bestbuy because it was still under warranty and they gave me a new one with no hassle. Yesterday ago I saw that my old psn name that I haven't used in almost two months had a last sign in of a few hours ago. I thought to myself I must have rolled over on the bd remote when I was sleeping, its happened before. However, last night I saw my old psn sign on while I was on my new psn. I thought that someone one must have hacked my old account somehow. Then over the next few minutes I saw my brothers psn sign on and off. And my cousin's psn sign on and off. I called them and neither of them were on. All of our accounts were on that broke ps3, this was back when neither of them had a ps3 and use to come over and play. Because the ps3 broke and wouldn't turn on, I couldn't delete our accounts from that ps3 before I returned it. So I'm thinking that Bestbuy must've fixed it and sold it as refurbished? The only thing that concerns me is that I had my cc info attached to my old account. This person could potentially have my cc info, if I went to bestbuy would they know what happened to this ps3? I'm just pretty shocked that they would sell a refurbished ps3 that wasn't restored to factory conditions.