You bought a ticket for Void or Icon? You can't 'accidently' buy a ticket. First of all, you are brought with the lottery page, which has a description and a list of all the active lotteries. Then you have to click on which lottery you want to enter. This page will show a button for buying a ticket. Once you click the button a message will come up with confirmation on the purchase.
You either bought 2 tickets from void or icon lottery, or one from both. This is impossible to buy a ticket without knowing that you are doing so.
If you are wanting a refund, then that won't happen I'm afraid. Be careful next time.
I bet you end up winning it now, or something. ;)