Thank you for contacting me with this question, I will be glad to help you.
We are a U.S. based seller and receive our shoes directly from Asics so, like all the merchandise we have for sale, I can confirm that these shoes are 100% authentic.
Most of those people that left such a feedback are fraudulent customers looking to get free shoes or dishonest customers who got the wrong size and did not want to pay for any return shipping costs.
We do not tolerate threats, so those customers did not receive anything from us and have been banned from our network of eBay sellers.
Our negative feedback ratio is only 0.2% of our total feedback, so I hope that is enough to give you confidence in our products.
We appreciate your interest and I hope you have a wonderful day.