You may claim only ONE reward at a time for any loyalty program. In order the claim the reward, turn over the pass and click "Check for new offers" - and then you'll see a page that will resemble the figure on the right. In this case, the loyalty club member has 200 points and can see available offers. Note that only offers 200 points and under are bold and selectable. The other offers are faded to indicate that you don't yet have enough points.
You should only claim a reward when you actually want to use it. For example, using the figure on the right, I could select an Iced Tea for 160 points. If I do that, then 160 points will be subtracted from my total and my pass will change into a reward pass indicating that I have claimed the "Iced Tea" reward.
This means that my next usage of the pass has to be redeeming the reward. I go to the store and ask for the Iced Tea (showing the loyalty card). When I get the Iced Tea, my loyalty card is scanned to redeem the reward and it changes back into a regular loyalty card and then I can continue to accumulate more points with future scans.