I recently migrated to NZ from the UK, and joined Telecom.
On my first trip abroad, I did what I do usually while abroad - leave my phone off most times, only turning it a few times a day to check for incoming texts.
Upon my return, I was shocked to see that my Prepaid Balance is significantly less than expected.
I rang Customer Services, who told me that I got charged because I have been rang. He said that although my phone is off, Telecom uses my last location to determine charges. As my last location is abroad, any voicemails received would be charged. Even when someone hangs up immediately after hearing "You have reached the voicemail of...." (Therefore I get charged $1 per call by someone else).
After much arguing, they refunded me the charges as an one-off, but honestly I am still unhappy that it occured. They suggested that I turn off my voicemail - which is unfair as I think a voicemail is useful when abroad.
On a more technical note: my understanding is that if my phone is turned OFF while abroad, Telecom will know about it (as my mobile phone will send a dissociation signal to the VLR, the VLR in turn updates Telecom's HLR). Therefore, any calls would only reach Telecom, Telecom would then divert it straight to voicemail (again, still in NZ) - there is no international routing at all isn't it? (Contrast that to my phone ON: in that case, Telecom would have to route to the Overseas operator, the Overseas operator would then have to re-route it back to the voicemail in NZ - I can understand a charge in this instance, but not when my phone is OFF).
Am I right about the technical part above?
Thanks for any opinion!