As the Speakers have failed thus a major fault you can ask for a refund now as 4 weeks seems quite a long time for diagnosis of the issue, and as their usage is most likely a daily one again the timeframe does not seem reasonable. The choice for a major fault of refund, repair or replace is at the consumer’s choice not the retailers. ACL is very clear on this major fault point. If they later determine that it was abuse by the consumer that led to the fault the retailer is within their rights to ask for the money back.
Even if the fault is minor you are able to ask for a refund, repair or a replacement but the retailer has the choice of what they offer.
If you decide to let them repair the item they are able to use refurbished parts to repair the device/s but before they undertake the repair they must give you an advice that they may do so. This advice might already be incorporated in their notice/receipt for the goods. This question has been asked already oin this site re the KIA car parts that @phb has linked to.
Re the relevant sections of ACL
" Repair notices
Under the Australian Consumer Law, businesses accepting goods for repair must provide consumers with repair notices when:
- the goods being repaired are capable of retaining user-generated data, for example, mobile phones, computers, portable music players and other similar electronic goods
- it is the repairer’s practice to supply refurbished goods rather than repair defective goods, or to use refurbished parts in the repair of defective goods.
The consumer must receive the repair notice in writing before the goods are accepted by the business for repair."
"Repairs
If the problem with a product or service is minor, you must accept a free repair if the business offers you one.
If the business fails to give you a free repair within a reasonable time or cannot fix your problem, you can:
- get it done elsewhere and pass on the costs to the business
- ask for a replacement
- ask for a refund
- recover compensation for the drop in value below the price paid."
"Replacements and refunds
You can ask for a replacement or refund if the problem with the product is major.
Replaced products must be of an identical type to the product originally supplied. Refunds should be the same amount you have already paid, provided in the same form as your original payment.
The business may take into account how much time has passed since you bought the product considering the following factors:
- type of product
- how a consumer is likely to use the product
- the length of time for which it is reasonable for the product to be used
- the amount of use it could reasonably be expected to tolerate before the failure becomes noticeable.
For a major problem with services you can cancel the contract and obtain a refund or seek compensation for the drop in value of your services provided compared to the price paid.
What is a major problem?
A product or good has a major problem when:
- it has a problem that would have stopped someone from buying it if they’d known about it
- it is significantly different from the sample or description
- it is substantially unfit for its common purpose and can’t easily be fixed within a reasonable time
- it doesn’t do what you asked for and can’t easily be fixed within a reasonable time; or
- it is unsafe."