Top up your balance of Tele 2 sim card by getting 1-year service extension.
After purchasing, you will receive a code as an e-mail code, which you can add to the Tele2 card in Tracker for Android app. Please note that you have Tracker for Android version 4.02, otherwise you will not be able to add extension time.
In the application, you can add the extension time by clicking > selecting collar with Tele2-SIM enabled -> Tele2 M2M. Enter the code you received in your e-mail and get additional validity time of 1 year on your SIM card.