To check your mobile service, track its usage and remaining balance, you may login to TPG My Account. We have created these articles which may help with your concern.
To reduce and prevent excess mobile data usages, please ensure to turn off your mobile data while not in use or close any apps that uses background data. You may not be using them, but they still consume data as it updates on the background (e.g Google drive, iCloud, auto-sync apps)
To help manage your TPG services on the go, you may download our TPG Mobile App on this link: tpg.com.au/services/tpg-app
Let us know should you have further queries.