Hi elysia2003 - I've replied to your question via email. Thought I'd reply to your post as well in case any other newbies are confused.
Your prize is automatically applied to your statement at 10am when you win the daily forum competition (pick 5 numbers comp). It will show on the last page of your October statement. Click on details under account balances, click on Oct 2009>, click last page.
It will look something like this:
21/10/09 Competition prize (Quanti forum competition prize - congratulations!) £1.00 Awarded.
You only have to claim if you win the random hourly competition - your username and an amount is shown on the blue banner.