The first step is to contact the seller and send photos through Messages on ebay. What you do after that depends on their response.
Was this a postal handling error? Or a packing error? The former is actually very rare. The latter is not.
It is the seller's job to insure shipments, not yours as the buyer. (Don't let them try to pull that one on you.)
If your seller is not helpful, you'll need to open an Item Not As Described Case. But don't do that without talking to your seller first, and giving them fair chance to fix it for you. No decent seller wants to shortshift their buyer. What they make in a couple of bucks per sale, they lose in standing and reputation if the buyer is left unsatisfied.
Again, talk to your seller first but always keep an eye on your window for opening a dispute. If the seller offers to send you a replacement, will you have it in time? The last thing that you want is a broken item, a missing-in-action replacement, and a dispute deadline passed. Then you are truly left empty-handed.
