On the 8th you can open a not received case, seller then has 3 days either to refund, or provide tracked proof of delivery, if not after another 3 days you can escalate to ebay.

Should your purchase arrive, this id the one time where if necessary you can open second case, NOT AS DESCRIBED, and that does include late delivery.

On every listing, right side there is a link to the money back guarantee, there is no reason to contact seller or worry when they do not reply. The 30 day money back guarantee, so long as used properly works and buyers do not have to worry about losing out to bad / poor sellers.