Hey, Smarty.
Let us try to fix this with basic troubleshooting, we did an article that will guide us on how to perform the steps, please see the link below.
Troubleshooting issues with Incoming/Outgoing Calls on TPG Mobile - https://community.tpg.com.au/t5/SIM-Only-Plans/Troubleshooting-issues-with-Incoming-Outgoing-Calls-o....
Let us know how it will go.
