The seller used very bad shipment provider SPSR express and DPD. SPSR and DPD shipped back the product back to seller without notification. I had to prove evident things for over one month.
The first media player was defective. The sound in movies didn't work. I opened a dispute and the seller offered to send me another unit. I agreed and closed the dispute. But the second unit had exactly the same problem, and, as I had confirmed that I had received the first item, I wasn't allowd to open a new dispute (more than 15 days had passed). Luckily, Aliexpress customer department took into account my claim and I received a complete refund.