My plan includes 100 min for international calls and I had been making calls to the same number with country code +86 and area code 512 for years, but suddenly since the end of April, my calls to those numbers end without a ringing tone.
I've tried to use a friend's mobile (Telstra) to make the calls to the same numbers, and it works. And I have confirmed from the receiving party that my phone number is not blocked.
On the 26th and 27th May, my calls to those international number worked twice, but it's now back to the "call ended without ringing tone" state.
