"It's nothing to worry about. On the left side of your "my account" it will show how many helmets(arrows/rewards) you've earned in the past 7 and 30 days, each day that goes by obviously it's going to be deducting from that number because It's a new day, so its not actually deducting points off your account it's just removing points off that rewards tally."
"So you know how in the homepage of the UN website you can see "points earned in the last 7 days" or "31 days" something like that. Well everytime that 7 days or 31 days are over cause it hits 32 days or 8 days they expire on those list. For your overall points it's still there, your points are just no longer there for the 31 or 7 days thing. It's really nothing to worry about :)"