Sony insists there is 'damage' to my carefully used headphones

It will not accept that the manufacture of the 279 pair may just be below par

I am three months and 16 emails into an exchange with Sony that is going round in circles. In December last year I purchased a pair of WH-1000XM3 headphones which began to show signs of unreasonable wear this August.

The plastic casing on both arms popped out, leading to the ear cups hanging by an exposed wire. It doesn't seem right that a pair of headphones costing 279 would be in this state after eight months of careful use. Sony replied with an ominous Please note that this, from our end, will be considered as potential physical damage" thus presupposing the customer, and never the product, is at fault.