Mazda has been found to have engaged in misleading and deceptive conduct and made false or misleading representations to consumers in the Federal Court.

Nine consumers who had each requested a refund or replacement vehicle from Mazda, after experiencing serious and recurring faults with their new Mazada within a year or two purchase, were ignored or rejected by the car giants, telling them their only remedy was another repair.

This was in spite of the fact that their cars had already undergone multiple unsuccessful repair attempts, including complete engine replacements, with one of the vehicles undergoing three engine replacements.

After repeated attempted repairs, over months and even years, in some cases Mazda offered to refund only a portion of the vehicle's purchase price, or offered a replacement vehicle only if the consumer made a significant payment. The court found this breached the customers' consumer guarantee rights and will decide on penalties for this behaviour at a later date.

In total, the court found that Mazda made 49 separate false or misleading representations relating to the nine consumers.

"Mazda engaged in long, drawn out discussions with the consumers, often multiple times a day over months, in which it misled the consumers about their rights," Australian Competition and Consumer Commission chair Rod Sims said.

"Mazda's conduct towards these consumers was not just appalling customer service as noted by the judge, it was a serious breach of the law.

"The message to the new car industry is clear, consumer rights are not negotiable and must not be misrepresented to consumers.

"If a vehicle cannot be repaired within a reasonable time, or at all, consumers have a right under the Australian Consumer Law to a refund or replacement."

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