That is totally irrelevant, the fact you had to shell out to replace their defect makes it worse.
Unfortunately at that point, having been in similar places, you have to turn into a bit of an a*se to get stuff done. Fender are very big on social media with their 'fender play' adverts and the like on twitter and facebook. On all of those adverts you see like that, reply to the post with 'How can I play this as my 2 year old £900 fender flea bass neck warped and it appears they aren't expected to last over a year' and similar. And on their page, comment on any post where people ask about their basses with things like 'Be careful, the necks are only supposed to last a year until they break' and the like.
do that and you will find that their response speeds up drastically. For some reason (and I think it is a shame), customer service of many modern companies is entirely driven by their social media profile, the person who waits and shows them respect appears to get nothing.
I hate doing it, but it works very well.