papillon surely if the deliver to your local Waitrose the driver could up/return from the same store, the reverse to the delivery in the first place..
I think under the circumstance’s/distance I would get on to J Lewis customer service to arrange a refund/return or replace the faulty item as your not going to/or should be expected to drive 50 miles on there faulty product..
For me a repair wouldn’t even be a consideration for me tbh..
Sorry to hear of a problem hopefully they can sort something out, usually they’re very accommodating I found..
Best of luck with it