[mothered]

I'm just thinking would it have been better to go down the route of contacting CS saying you received an older model. Hence the liability is pushed more over to their side immediately rather than being a greater liability on your end

Absolutely, and as stated In my previous post:

Did you "specifically" say that you returned the box In the same condition as when you received It? In other words, you've returned what they've originally sent you, hence they're at fault.