Seller contacted me immediately after I expressed my problem and offered a replacement. It arrived lightning fast. Overall I'm very pleased with their customer service and their product overall (which works well now), and I'm raising my rating.
UPDATED Jul 20, 2019-
Left ear stopped working after 7 months. Still got 7 months of reasonable use, so rating a 3.
UPDATED Dec 2018 -
The seller contacted me, suggesting I try a different music device to solve the problem of previous skip (see review below). Lo and behold, my problem was solved! I therefore upgrade my rating from 3 to 4 stars. I still think it takes too long to skip to next song/previous song (you have to press the button for too long a time), so I'm giving it 4/5 stars. A note that the skip problem ONLY happens in Spotify (not the Google Play Music app), and only with this pair of earphones.
ORIGINAL REVIEW: These would be perfect if not for the design flaw which makes it nearly impossible to go to the last song. Color is gorgeous - a true rose gold. With the included earpad hooks, and when clipped onto clothes with the included clip, the earbuds won't budge from the ears, making them ideal for working out/exercising. I've done high knees, burpees, rock star and cannonball jumps, and these stay in my ears. The sound quality is good too, and it paired quickly with my phone. The buttons allow for play/pause (top button), power off (top button, long press), volume up (middle button), next song (middle button, long press), volume down (bottom button), and previous song (bottom button, long press). Unfortunately, no matter how long or how many times I press the "previous song" button, the earbuds will go to the beginning of the playing song--not the previous song. I've tried pressing this button multiple times with different pressing patterns, and simply get the same song playing from the beginning. I've even gotten a replacement from Amazon with the same problem, indicating it is a design flaw of the earbuds. Also, for the previous/next song, you have to press quite a long time - 3 full seconds (it's generally shorter in the other earbuds and headphones I've tried - 1.5 to 2 seconds). In general, I don't understand why earbuds/headphones have the short press as volume, long press as previous/next song (rather than the reverse) - I think people are far more likely to skip a song than change the volume!
I'm going to have to return these - if they fixed this flaw, I would definitely keep them.