Telecom's public image may take another hit as an audio clip of Theresa Gattung circulating on the internet has the chief executive admitting to the company "not being straight up" with customers.

"Think about pricing. What has every telco in the world done in the past? It's used confusion as its chief marketing tool. And that's fine," said Gattung in a speech recorded on March 20.

"You could argue that that's how all of us keep calling prices up and get those revenues, high-margin businesses, keep them going for a lot longer than would have been the case.

"But at some level, whether they consciously articulate or not, customers know that's what the game has been. They know we're not being straight up."