Payment was just sent thank you

Got a question, one of my room-mates showed this site, he created me a account I bought some bitcoins from him he sent to me. I win and withdraw it and still haven't got it. It says they are sent the top of every hour it was about 3 hours ago. I withdrew a smaller amount and that was sent. but still not my bigger one. Should I be worried? How can I attach a screenshot to show? the amount was .13