i bought it directly from samsung experience, in india. and im pretty sure everything was normal like the csc code back in india. when i purchased the tesco sim it asked me to reset as it had to change the csc code
It's my opinion then it wasn't actually a Samsung Official store but a shop with the Samsung banner above the door that specialises in selling Samsung products.
A factory reset as I mentioned will not change or affect the CsC Code in anyway.