I've recently moved over to Australia (and have a new Australian number on Telstra (Woolworths MVNO) and am trying to contact people back in NZ. For some reason SMS messages from 2degrees numbers won't be received by my phone over here. Telstra have told me the issue is with 2degrees - and 2degrees appear to have found this to be the issue too, but it hasn't been resolved for 1 month +. 

MMS messages work fine, so do calls and SMS messages from Aus to the 2degrees number. The issue doesn't apply to other NZ providers however. Therefore everything appears to be configured correctly on my end (and the issue has occurred with multiple 2degrees users we've asked to try for us)

Anyone got any advice or input on why this could be happening and what could be done to fix it (or extra info we could provide to 2degrees)? They aren't in constant contact about it, we keep having to ring back and check the status (were told it was resolved last week but it hasn't been) which makes progress frustratingly slow.