How can I fix my company owned tablets?

I have 4 tablets that are basically locked and I am not sure what to do now. The former employees logged in with a Google account and after resetting it I have to log in with their old account. I do have access to Google Admin, but I have no idea which company email or former employee used these tablets. The person before me did not keep good records.

I called into t-mobile as we purchased them through them and they referred me to Samsung support. Samsung told me that I just needed to take proof of purchase and the tablet to a Bestbuy to have them unlocked. So I booked an appointment and the guy at Bestbuy ended up telling me that he is unable to unlock it.

Turning to Reddit to see if anyone else has any suggestions.