There's a lot of assumptions in the previous post. The most glaring of them is that one expects to have counterfeit products replaced by Antigravity, and that everything bought via amazon is actually sent by Amazon and not from the vendor, that anyone looking for an exchange is trying their luck with counterfeit products, and, finally, it is implied, that whenever Antigravity says they won't replace a battery it is because it is in reality a counterfeit product.
Seriously, Antigravity refuses to warranty any battery not bought directly from them. The problem with that, of course, is that far from all resellers deal with counterfeits. It's ridiculous to assume so, and it's ridiculous to defend that sort of behaviour from a manufacturer. It's not like Antigravity is a brand so well known and lusted after (like Louis Vuitton (spl?) handbags etc) that everyone can get a copy for about a tenth of the price. And it's not like they refuse to sell them to retailers/resellers, hence they have a legal responsibility to warrant their products. They try to get away with it, and has so far done that - not least aided by apologists who try to argue this behaviour is not only okay, but that they should be applauded for it, and the people with shoddy products from are always buying counterfeits, and are at fault (this time because they "always go for the lowest price"). It's only a matter of time before they will be called in the media, and perhaps face a lawsuit from someone who has both time, energy, and money, and are doing it out of principle.