Vodafone appear to have resolved the issue at their end, Telecom are still working to resolve theirs.
Monday August 15th NZDT 12:17
We are currently experiencing an outage with Telecom and Vodafone NZ (starting around 12:17pm). All other carriers are unaffected at the moment. Your pending messages will be queued & will be delivered when the connection is back up. Currently we have no ETA for this issue to be resolved.