a question about ebay!!?

[LEGEND]

OK so i have a business and we sell on eBay and recently we have had a huge number of people saying they haven't received our packages, I know there are some people who actually receive it but pretend they don't so they can get the item for free plus a refund, we send our packages 2nd class, so if they tell us they aint received it then we have to give them a refund, CAN PEOPLE KEEP DOING THIS ACTUALLY RECEIVING THE ITEM AND SAYING TO US THEY HAVEN'T SO THEY CAN HAVE IT FOR FREE, CAN EBAY CATCH THEM OUT AND PROSECUTE THEM OR CAN THEY KEEP CARRYING THIS ON, bye the way we are sending our items 1st class recorded now