I bought secondhand designer shoes online, but within a few months they fell apart. What are my rights?

Last year, I bought a pair of leather designer shoes from Vestiaire Collective. They passed Vestiaire ’s authenticity check and when they arrived they seemed fine. However, as I wore them over the next few months, it became clear they were not at the standard of a genuine pair of that designer’s shoes: first the body of the shoe came away from the sole on one shoe, then the other. I wore them in the rain and the glue seems to have practically disintegrated. Now the shoes are unwearable.

Vestiaire’s terms state that you need to contact them within 48 hours of receiving the item if you have doubts about the authenticity – which seems a very narrow window. I contacted Vestiaire to see if they could help me, but never received a reply. Given their reputation is based on selling genuine designer goods, I’m surprised. Is there anything I can do?

– Nadia from Victoria

Kat says: The rise in secondhand marketplaces for quality goods is an excellent antidote to fast fashion, and I think a great step towards extending the life cycle of preloved clothing. It doesn’t come without its drawbacks though – some argue it can encourage a “throwaway” culture as consumers buy and then sell unworn or barely worn clothes in a seemingly guiltless process. It can also leave buyers and sellers susceptible to dodgy practices, especially in international marketplaces where intermediaries like Vestiaire Collective facilitate sales between private individuals.

In your case, I think what’s happened to you has two elements: one, that the shoes may not be authentic and two, that the shoes have failed the pub test when it comes to a purchaser’s reasonable expectations of what shoes should do.

In relation to returning an item that “doesn’t match it description”, Vestiaire’s website says you can make a report within 72 hours of delivery for private sellers, and 14 days for professional sellers. While these timeframes have lapsed for you, it doesn’t necessarily affect your case.

Related: My speakers don’t work properly and Apple won’t provide a refund. What are my entitlements?

Critically, a business cannot create rules that undermine the Australian consumer law. Vestiaire has headquarters in Paris, London and New York, but the ACCC says “when an online business is based overseas and provides goods or services directly to consumers in Australia, the business must follow the Australian Consumer Law.” In this case, if the item you bought is truly inauthentic, then the business has engaged in misleading conduct – whether they intended to or not.

Misleading conduct, according to the ACCC, is when information given by a business to a consumer “creates a false impression about goods and services.”

If you haven’t already, you be able to try going through an authenticity check with Vestiaire, which doesn’t seem to note a timeframe on the help page .

If this doesn’t work and you believe the shoes to be inauthentic, build your case, and put it in writing to Vestiaire through its customer care function. What would make the shoes authentic? What is missing from the shoes that makes you think they are inauthentic? Take and include photos in your letter, and remind the business that the Australian Consumer Law applies in this instance.

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Further, under the Australian consumer law, there are consumer guarantees which mean when you buy something, you have a right to expect the product or service will work in a certain way. This includes that the product must be of an “acceptable quality”, which means it should be safe, durable and free from defects and does everything that similar products are commonly used for.

When it comes to shoes, designer or not, a reasonable person would expect a pair, with normal wear (if you were to do extreme sports in them, it might be different), to last more than a few months. And unless it is expressly stated by the business selling the product, it’s reasonable to expect that a pair of shoes wouldn’t fall apart in the rain. So you definitely also have the consumer guarantees working in your favour, and you should include this in your letter.

Under the Australian consumer law, you have a right to repair, refund or replacement. Given the shoes are secondhand it’s unlikely Vestiaire will be able to get you a replacement, but you should ask for a refund. The worst case scenario is that Vestiaire insists on the shoes’ authenticity – in which case, you are still entitled to a repair, at no cost to you.

You definitely have a case. The difficult part will be getting an international business to cooperate. You should also use social media to your advantage: messaging the business through private messages and in public forums is often more effective that going through the official contact channels they provide on their website.

If you don’t have any luck with Vestiaire, the next step (no pun intended) is to make a complaint to the ACCC or Consumer Affairs Victoria .

• In a statement, a Vestiaire Collective spokesperson said they had not received any communication from the reader about the shoes but have since contacted her directly. The spokesperson said “lower value” items do not typically go through an authenticity check, however customers can raise questions about an item’s authenticity at any time after purchase.

• Kat George is a board member at Australian consumer advocacy group Choice. Her Guardian column is written in her capacity as a policy expert and does not reflect the views of Choice

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