I'm in the States at the moment for some urgent business, before I hopped on the jet I figured I'd snatch a 2degrees SIM to avoid some hefty charges.

My debit card got blocked today presumably for international usage, decided to try out 2d's wifi calling. Connected my iPhone to WiFi, toggled on WiFi calling and flight mode, made a call to 200, the call went out without a hitch. Then I tried to dial my bank's 0800 number, the call failed, weird I thought. I figured that might be down to my balance of zero, so I made a quick top up and the call went through without a hitch.

When I finished the call I jumped back to check the degrees app, I was surprised to find that I was charged $0.49 * 3 for my call.

My understanding is that making calls to 0800 numbers within New Zealand should be free, and if I make a call via WiFi calling I should be treated as though I was calling from inside New Zealand, so the call is supposed to be free for me? Or am I missing some caveats here?

I wasn't charged for an inbound call for a friend of mine tho, so I'm pretty sure WiFi calling is on and working. (I turned on flight mode to be extra sure). I've called up customer service they've agreed to refund the charges but aren't willing to investigate any further. Could anyone please shed some light on this particular issue?