Unclaimed reward

I'm supposed to have $5 reward, but when I did walk for 30 minutes  and tried  to check on my points, it was not showing anything. I tired to check what happened, clicked on some info to find out but after sometime all my data disappeared including my  $5 reward. I tried to enter my data and info but everything turned to zero. Is this scam? I got my  $5 reward before but this time I  don't know what happened. Pls explained what happened and how can I retrieve my $5 reward. Thanks!