I'd suggest to contact your regions Samsung Support Team and they'll advise what's happening with the serial number and warranty status.
All Samsung phone's automatically come with a limited 2 Year Manufacturers Warranty, however to gain support under this warranty most Service Centres ask for proof of purchase.
If I can be of any further help then please don't hesitate. Take care. 😎
Daily Driver > Samsung Galaxy s²³ Ultra 512Gb in Phantom Black.
The advice I offer is my own and does not represent Samsung’s position.
I'm here to help. " This is the way. "
Hi @nannydonut. If your Samsung account has a different email address to the one you would like, please contact the Accounts Team on 08009951079.