When I Pre Ordered the N20 Ultra from Samsung UK on their online website one part of the ordering system was to choose the freebie I wanted.
I chose the Samsung Live Buds and they came a short while after the phone which I think is a better process than waiting for a voucher.
I've read some others have been offered a voucher as a Goodwill Gesture to buy an accessory off their website but unfortunately the voucher came nowhere near the cost of the Live buds !
When I had to return the N20 Ultra along with the free buds Live I encountered unacceptable issues.
After speaking initially with customer services via phone and several emails with little resolution I searched out the CEO email contact us page.
After filling that out my refund followed a few days later.
It's of course upto you how you wish to proceed.
I wish you all the best with this.
Current Phone > Samsung Z Fold³ 5G.