Back of watch cracked

My series 6 Apple Watch back has cracked. I haven’t even had it a year yet, it was brought in October 2020. I haven’t dropped or stood on the watch and I am very careful with it. Can anyone advise me on what I can do to get it fixed? Even though it’s still in warranty I’ve been told I have to potentially pay up to £300 to have it repaired as Apple only repair for software damage. I don’t want to pay half the money I paid for the watch brand new. Any help would be greatly appreciated.