Have you already got a Samsung?
I contacted them (the Samsung shop) to ask for a price to replace the charging socket on my old phone. They verified my serial number and offered me 15% off the (Currys and Argos) price of a new phone instead of mending the old one.
I have my various Samsung products registered on a Samsung account.
They did not specify which model
I got a SIM free A52S, which takes two SIMs, and a SIM from Virgin via Martins moneysaver. It was £10/month cheaper than my Vodafone contract, although Virgin are now on the Vodafone network.
Martin also has PAYG SIMs, cheapest was via ASDA, also on the Vodafone network. I have one for the car. Also handy for people visiting from abroad.