The relevant fine print is at the end:
Point 18 was probably already there originally, then they just added point 20 and that was that!18. eBay reserves the right to vary the terms and conditions of the offer at its reasonable discretion by publishing revised terms on ebay.com.au.
19. The parties submit to the non-exclusive jurisdiction of the courts of the state of New South Wales.
20. These terms and conditions are revised as at 30 December 2015 and effective immediately.
They could've at least sent a warning email to say the terms were revised, but they weren't even assed to do that!