G3 new battery issue.

Bought a used G3 about 3 weeks ago. Needed a new battery as spare so ordered a Duracell direct from Amazon (not third party). It's faulty. If I put it in charger, the green light starts flashing. Manual says either clean contacts, or temperature is too high or low, which it isn't. Been on charge for 2 hours, but no increase in the single bar showing. Original Panasonic battery charging Ok so not faulty charger. Is there compatibility issue with these Duracell replacements? I thought Amazon didn't sell fakes. I have said I'm returning it. I'd hate the replacement to do the same. Advice appreciated.
Regards,
Colin.

Easy. Return it and order a replacement. If that's also faulty, also return that, telling Amazon why, and look elsewhere.

Thanks.

Amazon is full of counterfeit stuff.

I know. I was careful to choose Sold By Amazon, on a battery I won't even do Fulfilled By. So I guess it's just faulty. Can you get fakes sold by Amazon (not third parties)? For example, if they were out of stock and a fulfilled by Third party had one in the warehouse. They asked me to print out a return label, knowing it was L-ion battery. After printing it out, the notes said to contact customer service as it was a defective L-ion, and they told me to dispose of it at a waste disposal centre as it's a defects. Why couldn't they have asked me if it was faulty on the form I filled in, and then told me to recycle. Two sheets printed, and a lot of Sellotape wasted. Anyone know if anything can be done to fix the battery, like letting the small charge in the battery run down and then trying to charge it up?