So, around July 13 2022 the "Pledge Manager" opened, you should have an email about this, but it's also on the KS updates:
https://www.kickstarter.com/projects/steamforged/runescape-board-game/posts/3543583
This was administered through "Gamefound" (not backerkit as I previously stated!)
If you didn't fill out the pledge manager on Gamefound, you won't have anything dispatched to you, because your address was not confirmed and you never paid for shipping.
Reminders for pledge manager closing were issued on Sept 13th 2022 and Oct 24th 2022. Looking at the updates, it seems like pledge management was re-opened May 30th 2023, reminder at June 20th 2023 and then finally closed a couple days later June 23rd 2023.
Check out this link, and you'll probably see that you have £65 in credit.
https://gamefound.com/en/projects/steamforged-games/runescape-kingdoms-shadow-of-elvarg
It's possible that support at SFG can help you work through this - but you'll 100% need to raise a ticket with their helpdesk, and it seems like tickets are in a weeks-long backlog right now.
You can raise a ticket here
As long as you get the auto-responder, you're in the queue, just be patient with the team, things are super hectic right now. If you've not heard anything in a couple weeks, then perhaps ping one of the staff here. I'm not sure what the process is right now, as it seems staff are pretty overwhelmed.
Anyway - hope this is at least a little helpful 