Refurbished Cellphones

Vodacom have to take blame on sumsang phone I bought from Dunns because I suspect that Dunns sold refurbished cellphone to me. How can a brand new phone decline the registered email address that was used as first email to the phone as brand new!? the cellphone didn't have settings menu which i cant do settings and connect to Wi-fi, I took the phone back to Dunns store were a Manager performed a reset from factory, flashed everything and when we try to log the email ,the phone's google refused the email which was the first email used that cellphone first day from shop, according to my knowledge about google security is that a phone keeps first email as a security and if you could give or sell it to someone if that second owner decide to flash the phone memory for the second person to be able to use the phone, first email will be required.