Well after my last post I rang Umart and asked what I was supposed to do with a drive that didn't store data. They said they couldn't return it without an error code or an obvious fault so there was nothing they could do. It was suggested that I email Seagate support and if I could get them to email me back saying to return it then they'd RA the drive with the email attached as the reason.
I'd check my emails for a reply except the Telsta mail server is in its usual state of "down". So no emails for me!
Maz