Eneloop Not Charging Properly - Who to Contact?

I've been using a pair of eneloops for my Oculus quest controllers (one in each controller) but one of them seems to be discharging super quickly. I normally charge them at the same time on a LIitoKala Lii-402 and the faulty one doesnt reach full charge on the mete.

Do I send it back to the retailer, or is there a Panasonic contact I should talk to?