An update on the situation that I have:
Optus
Using MyAccount,
https://www.optus.com.au/customercentre/myaccountlogin, I couldn't get it process less than $1.
Using Paymybill,
http://www.optus.com.au/paymybill, was working fine for a few days with 1 cent transactions but now seems to have changed to $1 too.
Are there any other Optus options? Which are you using
benjy?
Telstra
I have a script working for 1 cent transactions but I can only get it to work online. Previously I was getting Optus to run overnight but can't seem to get Telstra to work that way.
Water Company
Accepts 5 cent transactions as the minimum. Easy to script but seems to only allow 1 an hour or so. I'm still trying to determine the time that must lapse between transactions.
Energy Company
Accepts 5 cent as the minimum. I haven't bothered scripting it as yet.