I can't quite work this out. Seems if you move your mobile number to contact, they'll give you $300 credit on your electricity bill.
All their plans are open term.
They seem to have a $40 a month plan, so in theory one month and you could bail?
We’ve got something special for you for being a Contact customer. You’ll ring up a $300 energy account credit when you bring your mobile phone home to us before 30 April.^
All you need to do is join Contact mobile using the same name and email address that you use for your energy account. Have your energy account number handy as you’ll need to enter that too (you can find this on your last bill). We’ll add your $300 credit to your energy account within 7 days.
^ Promotion only available to new Contact mobile customers. Contact reserves the right to cancel, modify or suspend this promotion at any time and shall not be liable for any loss or damage incurred as a result. The credit is not transferable, refundable or redeemable for cash or cash equivalents.
They have WhatsApp and Messenger. Have pinged them to see what they say.
If this works, you could technically just get a throwaway SIM for like $1~$2, bring multiple numbers across and earn $260 of profit per number, then cancel your plan after 1 month.