Do you keep being returned to the packages page? This will be because your payment was not completed by your bank or financial institution, so although you have an account with us you do not yet have an active subscription. All you need to do to get up and running is select a package, make the payment and then the device you've added should begin tracking and you'll be able to access all of the features available on Device Tracker Plus.
Alternatively, it could be that your card has expired or your payment has failed. If you'd like us to check for you please get in touch HERE and one of out friendly customer advocates will be happy to help you get back up and running.