iphone 5

so i brought a Iphone 5 from Telecom

EveryTime i ring out it Says the number you have dialed is barred

so i rang telecom telling them about my problem

And they didnt help at all so far i know the phone is unlocked

Because i inserted a Vodafone Nz sim in to see if it would work yet it still continued to say the number you have dialed

is barred i have a 1 year warranty would i be able to get a replacement phone or get it repaired so disapointed to spend $1029 on a phone that cant ring out but can recieve messages -.-