Sorry to hear about your problems. The battery can almost certainly be repaired without scrapping the cells, but sounds like you are stuck dealing with a manufactured part with a deficient design. It might take them some time to issue a technical fix, which unfortunately is of zero help to you in your current situation.

It is almost certainly possible to replace the PCB with a different battery management system. Would be a pretty common thing in the DIY community. But you should not have to do this and doing so will unquestionably void any warranty on the expensive battery. If you could go back to the original bike shop one would think they could pull a battery off another unit in the shop, but that would be an unreasonable request of a shop that did not sell you the bike.

It is this sort of thing that makes me glad I don't worry about warranty repairs, although with something as expensive as a battery I might be more insistent they make it right.