Apple has released a new service policy, which will allow Apple watch Series 2 swollen batteries to be repaired for free. This only applies to the 42mm variant of this series.
Apple implemented a similar policy regarding those as well. The repairs must be scheduled through the Genius Bar and it is recommended that customers ensure that it will be a free repair prior to agreeing to service. There were reports of some employees not being aware of the new policy. Naturally, the device must be inspected by Apple employees to confirm what is causing the issue. The watches are sent off site to be repaired so you may be without your device for some time before having it returned.
