Another launch day iPhone X user here, who has also experienced the ‘swollen battery’ issue in the past week or so. Reading the comments on this thread makes me wonder if the lifespan on the batteries from the launch phones is <3 years? I was surprised to experience this problem (identified when the screen lifted away from the body of my phone), as I had not noticed/experienced any noticeable deteriation in battery performance. However, the service from Apple has been very good.
I took my iPhone X into an Apple Store last Wednesday (genius appointment), where they confirmed that the issue was a swollen battery & advised that for £69, they would send the phone away for ‘repair’, but that I would actually receive a whole unit replacement...and this process could take up to 2 weeks. Felt a bit anxious at the thought of being without a phone for 2 weeks & I seriously considered buying an iPhone SE on the spot to tide me over (the guy at the store said I could return the SE within 2 weeks)...but then I thought, ‘get a grip’...buying another phone with the intention of returning it would have been a waste, plus, I managed to survive the first 35 years of my life without a smart phone, so I should be able to go 2 weeks without a phone.
The good news is that I received my phone back today, just 6 days after taking it into store. There was a printed note in the box with the phone, which stated that they had replaced the battery, display & speaker, thus, it appears that they actually repaired the phone & did not simply send a whole unit replacement (the serial number of the phone also matches my original phone)
I did have a Belkin screen protector fitted to my phone (previously fitted via a machine in-store). The guy at the store kindly offered to put a note on the system about this & advised that the store would be willing to fit a new screen protector (free of charge) after I had received my phone back. Popped in to the store this afternoon & they kindly fitted a new screen protector at nil cost & with no questions asked
Now need to decide whether to stick with my iPhone X for another couple of years, or whether to switch to the rumoured 5.4inch phone if/when it launches in the Autumn. Really like the idea of having a slightly smaller ‘full screen’ iPhone, but given that I now have a new battery & display, the sensible part of me is thinking I should just stick with my X & save some pennies