Klarus 2PA tail switch failure...

During the recent offers from banggood, I purchased a few 2PAs which were snapped up by my work colleagues. They are brilliant, and so much more robust than the overpriced lensers from snap on.

Sadly, one has a failed switch - it simply will not click or pass current.

Although I’ve not yet managed to remove it, as the retaining ring appears to be very tight, I was wondering what the best course of action would be…

I see there is a returns area on the Klarus site, but is it really a viable option from the UK? If not, does anybody know which switch this light uses?