Score a possible $50 credit on your Amaysim account - technically a facebook comp.
The comp runs every Thursday until 28th of Feb. To enter you need to answer the question posted. Todays for example is "What song would be your ultimate summer ringtone and why."
Three winners will be chosen for the $50 credit, which can be applied across any of the Amaysim services, based on creative, insighful, amusing or inspiring rulers. The decision is discretionary on the marketing dept. I reckon you've got a reasonable chance of success on this one as the volume of entries cant be that big.