The internet may be the final frontier. Not all the possible legal issues in cyberspace have been resolved yet. One might contend that the ebay EULA is an adhesion contract. It certainly lacks any real "meeting of the minds" or even a level playing field for those who wish to conduct e-commerce with it. Where is the consideration each party should give for a valid contract? Perhaps if you continue to correspond with them, you may be able to resolve the dispute amicably in a satisfactory manner.
[Due to the limited format of Avvo, this is not "legal advice", nor does it form an attorney-client relationship.]
You conduct your business as a private commercial enterprise. So does eBay. The agreement between the two of you controls what you can do, and what eBay can do, with respect to the storefront that you created on eBay's servers [thanks to eBay, by the way, for creating the opportunity for you to even do business via the internet]. That agreement was written by eBay and you agreed to it. Some of the terms of that agreement are here:
You agreed via that agreement that eBay could shut down your store, or take down certain of your offerings, at his discretion. It has done so. You don't like that action, but you agreed that it could occur. Now you have to live with that reality and deal with the take down on its merits. Whether eBay's reasons are "vaild" or not is not your call. The take down was permissible -- the question is whether your offerings should be re-published. As to that question you need to work with eBay.
FYI -- eBay is not a public utility. You have no "right" to open an eBay store. The matter is wholly contractual. And if eBay does not want to deal with it you it most certainly does not have to.