Yeah, like I said, sometimes it can be very iffy when buying off of Ebay. Luckily, they have a "Buyer Protection" thing now, where if you receive an item that wasn't as described on the Ebay listing, or never received it at all, you can contact the seller and settle things with them. If you're not happy with the seller's resolution to your problem, you can go to Ebay's resolution center and they can sort things out for you.
Never had to use this as most of the time the sellers are more than happy to help me out and there was a logical and reasonable explanation for whatever went wrong.
For example, one time I payed for an item and after a week, it still hadn't been shipped. So, thinking that there might be a reasonable explanation for all of this (i.e. something happened at the other end and they had to delay sending it out). So, I sent them a message asking if everything was okay, being very nice an polite throughout, and sure enough, there was a logical and reasonable explanation.
Turns out the payment was sent to an old defunct account of the seller's and they didn't even know it. So, they got on the phone with Ebay and sorted things out and after the payment cleared, they shipped the item right out. I got the item a few days later and am still happy with it.