This has been argued many times. I have no problem with companies charging for CC fee as long as they are reasonable (ie represent the delta between the cost of them processing a CC transaction and processing the cheapest means of payment - BPAY). In theory, the base fee should be for BPAY, then surcharges implemented for cash and CC transactions. The Virgin Mobile fee of 1% does seem to be "reasonable" on this test.
A 2.4% for payment by credit card by big companies like QF is not reasonable - it's a classic case of having it both ways, especially given for companies like QF CC's gave them to direct sell and eliminate huge costs from their business, but won't go there.