You are not writing to Ebay here, just other members.
Like anything an adult chooses to purchase online, a potential buyer needs to do their own research into what they are buying and its suitability for what they plan to use it for.
Any item purchased which is advertised as working and doesn't is covered by the Ebay 30 day Money Back Guarantee.
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)