I mean if Big W advertises/sells something, it is they who are the ones who have to order it from from the manufacturer/warehouse in order to fulfil the demand for supply and ship/post it isn't it?, Not your company? - I apologise for any confusion dude.
My understanding is that you guys merely handle the website side of things (Website construction/maintenance, customer details, payment gateway etc.) and that stock procurement and shipping/posting is handled internally by Big W yeah? - i.e. Your company is contracted by Big W/Woolworths?