rhid, you won’t get any form of customer service if you go to the shop with the attitude you’re projecting (and being encouraged in) in this thread. Wind your neck in until you’ve spoken to the Shop.
Your wheel broke, so what, these things happen. The bike is 14-months old so I’d say it’s the Importers warranty not the Supplying shop that’s ‘liable’ – subject to Santa Cruz warranty conditions.
As for fit for purpose – unless you’re doing drops off house roofs or 20ft road gaps then the Heckler is FFP.
As for Pro II’s being problematic that’s nonsense. The number that are in use is, relatively speaking, immense. So a few failures are inevitable, only a moron would think otherwise. I’ve seen loads of hubs break, guess what from loads of different manufacturers.
As for wheel build costs if you’re willing to pay £50 just for a wheel build then send it my way I’ll happily do it for that price. If you decide to change the rim then the entire cost of the re-build is yours and Santa Cruz should just supply the replacement hub.
What I suspect will be offered is an entire new wheel in exchange for the entire broken one. Which is both fair and reasonable.