Locked out of my Samsung J1s

[AC Question]

So, here is the problem. I bought used samsung j1s locked to a network but not sure exactly. I want to use as a back up phone. It was working fine and everything was good. I did a factory reset and found out there is FRP(factory reset protection) lock there. The old user left his google account and didnt remove it but I was using without realizing that there is another account on it. So I am unable to use this device even I have tried every method that is available. I have tried OTG method, side sync method even some other method but non of them are working even when I tried OTG method nothing happens and same thing in side sync. I am stuck now not sure what to do. is there any one can help me?

 

[belodion]

Can the account holder be contacted? If not, and you bought from a retailer, demand a refund.