My faith in John Lewis has been shattered over TV refund

It made an ‘amazing’ promise after TV developed a fault and nothing has happened sinceI bought a TV from John Lewis in March 2015. It came with an extended five-year guarantee, which I topped up with the store’s accidental damage cover.Last November, the TV developed a fault. John Lewis attempted to fix it but, when it couldn’t, it offered a full refund for both the TV and the added cover – a total of £418. I thought this was amazing and had so much faith in J