Hey there, I am sorry that this is happening to you but this isn't necessarily a negative situation. I see that you have purchased the item twelve days ago (on September the 3rd). How did you pay for the item? If you paid for the item by credit card, then your payment will go through right away. However if you're like me and pay directly from your bank account, it will need three to five days to clear. Once the payment is clear, *then* the seller ships the item. Keep this in mind.
I know it seems like you got ripped off because when you went to go send the seller a message, it said that the seller was no longer registered with the account. Yes, this looks bad. However, eBay and Paypal partner up and have developed ways to deal with these kinds of sellers. Trust me, this is not the first time something like this is happening.
When this happens, eBay and Paypal do not just say "oh well" to the buyer and just forget about it. There is protection with both eBay and Paypal in order to ensure that the buyer is completely satisfied. I will give you some more information and links where you can find more information on how to deal with this problem below.
Click here in order to find out more information about eBay's protection program. This will help you solve this problem. All you need to do is file a complaint, telling them what happened. There are steps that you can follow on the page, it's really easy to do.
You can also file a Paypal claim if eBay doesn't help you out here. Click here to learn more about the services offered through Paypal to help deal with these kinds of situations.
On another note, two weeks isn't a lot of time for you to not receive your item. I've had to wait approximately a month for some of the items I have purchased on Paypal. Why don't you wait a little bit longer? The item could have possibly been caught up in customs or something like that. It's good that Paypal allows you to file a claim up to sixty days after the purchase - so you have quite a bit of time.
I hope I helped. If you ever need anything or feel the need to discuss this further, feel free to message me any time as my inbox is always open.
Good luck and I hope this works out for you!
DYL