My Samsung galaxy S4 is locked

Verizon Samsung galaxy S4 prepaid:
I don't know my Samsung account and my phone was unproperly factory reset and it'd locked I can't get into it I am able to get into browser and Samsung browser which I can use those to get into phone settings and I've done that removed accounts etc etc but when u reset phone like other sites have said the Samsung account is still on it I can't press the home button I've called Samsung they said I have to send it in and I'm fine with that if I able to find the prof of purchase due toy phone being bought 3 years ago I don't have the prof