Default [Q] Help! Device Locked Due to Abnormal Factory Reset

Hi all,

I am in desperate need of help with this AT&T Samsung Galaxy S5 that I found in abroad. Before I get chewed out with accusations of theft, I found the phone in a restaurant and gave to the staff who returned it to me after 3 days an no one had come to claim it.

Anyway, I have been trying to unlock it for use in Canada. I'm a bit of a noob, so please be patient Started with a commercial unlock code to SIM unlock. I received a "successful" message, so I assume it worked. However, I was told that AT&T locks other SIM cards from working on their firmware, so I began to try to flash and install a custom rom. I went to geohot's towelroot page and clicked the lambda. I think it did something. For some reason, I decided it would be a good idea to do factory data wipe from the volume down+power+home recovery screen. Now, I can't get past the initial setup which is asking for my original Samsung login ID, which I obviously don't have. In addition, I can't flash the rom with Odin or install off of external SD card.

Please help!!!

Thanks!
AK