My advice would be to use the call me back option to get on the phone to ebay, tell them you are not asking ebay to step in yet but would like some advice as a buyer has opened a return request some time after leaving pos feedback for a 20 year old piece of equipment and is now saying after having it for nearly a month and that of course something as old as that cannot be expected to last as long as a new item and that it is something easily damaged by the user. It can't hurt and they may agree to find in your favour. If they do make sure you note the time of the call and the employee's ame and number. If they don't agree try again a few hours later, often a different person will be more sympathetic.