NONE of this has anything to do with the sync rate between your modem and the DSLAM I really hate some RSP's support sometimes
Remember, in this case it's a company who isn't wholesaling but partnering. it's very much like Stuff Fibre.
If you need to raise a fault with them, it needs to go to Devoli to manage it as a Tier 2 basically..
When your a provider in that situation, you get all your tier 1 testing out of the way first. Possibly even blind (in terms of system tests which sounds like the case here)
Are contact energy just another VRSP through Devoli?