They wouldn't tell me on the phone the reason for closure.
After email correspondence this is what I received:
"Thank you for your email.
The circumstances that led to the closure of your account was the unusual use of your account to make multiple consecutive payment transactions at a very low value, some at one cent each, for payments that would ordinarily be paid by one transaction.
Your Qantas Transaction Account was closed under the relevant clauses in our Investment & Transaction Accounts terms and conditions.
With this in mind, the Bank has provided you a 14 day period to open a new facility with another financial institution before the account is closed by us.
Kind Regards
Customer Relations"