Sadly they have no email for enquiries and simply suggest phoning in office hours. Not an easy suggestion from the other side of the world!
Easier than you might think. your options are:-
Skype (on either a PC, tablet or mobile phone)
Google Hangouts (on PC, tablet or mobile phone)
A stand alone voip service using pc, tablet, mobile phone or dedicated handset
A phone card using any fixed phone or mobile.
For what it is worth, hangouts, the new kid on the block, has superb audio quality (as well it should running on Google servers and network backbone), the best way to use it is on your Android phone as if you have one of those, you already have a Google Play account - a phone call to the UK is around 3 cents a minute IIRC.
If that is not to your taste and you don't want to use a headset plugged into your PC,
www.engin.com.au can provide you with a VOIP router that you can plug a normal telephone handset into.
I have an Engin account - calls to other engine users are free, calls to any fixed phone in Australia is 10c. Mobile calls and calls to 1300 numbers are expensive (relatively) however.
I've just ordered a set of bump stop rubbers (and because Motorworks seem to be the only place on the planet that has them, I ordered 4 sets) and a set of heavy duty fork springs from motorworks.
I also ordered some bits that Motorworks didn't have form Motobins on the same day. It will be interesting to see how far apart they arrive and, after weighing the parcels, who has the better postal rate (I think it is going to be Motobins)