It isn't what the sellers says, or what you say that counts. On eBay, non-delivery claims are decided according to the tracking record.
If you haven't received your item by the latest estimated delivery date you can open a case under eBay's money back guarantee. If the seller hasn't agreed to a refund within three working days you can escalate the case for eBay to step in. The seller will be required to upload a tracking number that confirms successful delivery. If the tracking confirms that it hasn't been delivered, you will receive a full refund. If it states that the item was delivered eBay will support the seller.
If the item was stolen from your doorstep (it happens all too often) this won't be covered. However, if it was delivered to the wrong address you should be able to appeal, if you can prove this. Good luck.
