In a statement, ACMA said the fines and warning came in the wake of investigations into complaints found that each of the three businesses had contacted consumers after they had withdrawn consent to being contacted.
"Telemarketers must have the permission of the consumer involved to call a number on the Do Not Call Register. Calling a number on the Register without consent is breaching the rules," said ACMA chair Nerida O’Loughlin.
"Consumers have the right to withdraw their consent to accept or continue a call at any time. Telemarketers must listen to consumers and take their obligations seriously by removing people from calling lists when asked."
Penalties for breaches of telemarketing laws include formal warnings, infringement notices or action in the Federal Court.