Whenever I buy from China/Japan/Korea/Asia/etc. I sadly don't expect warranty/returns/etc. even if the company is well-reviewed by regular consumers too. It's one of those things that unfortunately happens way too often and so as much as possible I buy from Amazon (well, when it comes to IEMs I have no option but to buy from China unless I want to wait several weeks/months for it to be stocked in Amazon) and then talk to the customer service people there if I encounter problems.

IIRC Amazon will sometimes say they will give you a full refund even if you're past warranty/returns, though this depends on your account history (amount of spending/returns/etc.) or something like that.

Basically just open up the support chat even if it's been several months or a year or so since your purchase of the IEM/product, and then ask the customer service representative from Amazon if you can return the item, they'll usually do the process for you.

Wait a minute, did you buy from the ShenzhenAudio/etc. storefront on Amazon, you can talk to Moondrop/ShenzhenAudio/etc. there instead too but if they are still not responding after a week, just go with actual Amazon customer service.

Keep in mind that this out of return period warranty process is like dependent on your history with Amazon. As in you'll probably be able to do that if you spend a lot of money on Amazon and don't return that much or at all.

Like some of us get offered this: even if it's beyond 30 days or outside the October to January (some people apparently demo a lot of IEMs/headphones/etc. around this time as it's 4 months of free trial with the product, lol, but I don't recommend you do that as they will block your account if you do it often) extended holiday return period, Amazon will accept the return and just refund you what you paid.

Just try if it's available for your account, this is through the chat system by the way, and these days they made it so hard to find live chat support, lol. Anyway, some people also call to Amazon to complain, but for now just try the chat as it's pretty quick and automated there too.

For the customer service, some of the customer service reps will often be on the Discord servers, Facebook groups, and so on, and you can get in touch with them quicker there. A lot of them know each other and so they can help you reach the Moondrop people.

They will probably ask you to do return shipping to China but don't bother as it may get lost/et cetera, lol.

A lot of companies will go in circles just to deny you a proper new pair and so ya pretty much expect no warranties/etc. when buying from China/outside of your country.

Here's a bit more about ordering from AliExpress/Chinese companies in general: https://www.reddit.com/r/headphones/comments/zav570/is_hifigo_a_scam/iynrt65/ and https://www.reddit.com/r/HeadphoneAdvice/comments/uwk248/should_i_order_shuoer_s12s_from_conceptkart_or/i9t7zo0/

More specific to European customers ordering from AliExpress, but goes sorta in depth about express international shipping, customs fees, delivery procedures, et cetera: https://www.reddit.com/r/headphones/comments/xky24f/americans_and_europeans_ordering_high_end_iems/ipgtsuk

Here's a bit more info on AliExpress shipping times: https://www.reddit.com/r/HeadphoneAdvice/comments/uw4uq1/earbud_advice/i9q7fql/

Use parcelsapp.com and 17track.net to check your package progress. Usually it'll be a week before it actually leaves China by the airport and then the rest of the time is just waiting for your country's customs and the national/local mail delivery service.