Soundcore Liberty Air loosing battery after 15 minutes

I got these for Christmas and using on an iPhone 8, the case is fully charged but the earphones will run out after 15 mins, I can put them in the case again and it will say full battery but it still runs out just the same, any solutions?

Looks like you may have received a faulty set.

Please connect SoundCore Support service@soundcore.com

Do expect a delay in response, SoundCore may currently be closed for holidays, until Feb 3rd.