If you can prove that the listing offered free shipping to your location (by saving a screenshot of the listing--specifically, the shipping cost information--you can file a claim for "Item Not as Described," since shipping is part of the item description. You probably won't even have to "prove" it, but saving a screenshot of the listing is always a good idea.
When you buy an item from China, all bets are off, really. The estimated delivery date is usually so far out there that eBay can no longer help if there's an issue. Getting postage to return a item gets complicated. It's just not a good idea for any number of reasons.
While eBay may have denied your request to cancel, that is not an action on a "case." Did you actually file any kind of case through eBay's Resolution Center? Or did you just call and talk to Customer Service about cancelling? Alas, however, if you've opened a claim through PayPal, you may have voided your opportunity to invoke eBay's Money Back Guarantee. What kind of case did you file with PayPal? Refusing delivery of the item was not the best approach, since both eBay and PayPal will probably consider the refusal of the item to be just as good as an actual delivery.
