Hi, thanks for your feedback. According to your description, if your device reaches 69℃ after 45 min of power up and can only work for 15 min in 100mA mode, there's definitely a problem.
The seller is not our authorized distributor. We don't know who that is. And as you already saw, we mentioned not to buy from Aliexpress:
"Please purchase aune products from our
authorized distributors (
http://www.auneaudio.com/p/Where_to_Buy.html) and our
official Amazon (
amazon.com/s?me=A2AP0JEHTRG6EO) where the aftersales service is guaranteed.
Aliexpress is NOT recommended as the quality and aftersales service are not guaranteed."
Our authorized distributors pay customs duties, shipping, and other related costs when purchasing products from us to sell in their regions. If one doesn't buy the product through official channels and there's a problem with the unit, even if we as the manufacturer would like to assist him in contacting local distributors for aftersales support, it might be difficult for them to accept products that are not bought from them.
Therefore, products purchased through unofficial channels such as AliExpress have difficulties in obtaining aftersales support. If the seller is unable to provide aftersales service, returning the product to us in China would incur high shipping costs.
That is why we strongly recommend purchasing from authorized distributors or our official Amazon.
In your case, we suggest you to contact the seller for a return.
If the communication doesn't go well, you can directly contact us
sales@auneaudio.com