Welcome to the Community!
Please find the instruction below:
Go to Advanced> System tools > Administration >
Scroll down below to disable the ICMP ping as per below screenshot and save.
Should you require further assistance, you may reach out to us again or you may check out our self-help options located here: http://tpg.com.au/support
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