Urgent advice please

I am really at my wits end with the Wellington Immigration Service. I will try to explain, briefly!
We lodged our residency application on 7th Feb and heard nothing until 16th July when we were informed that further information was needed regarding our medical records. We were also told that a decision on our residency application would be made on 18th August even if they had not received the required information by then!

I duly made an appointment to see our GP and she advised me to have a further X-ray so the radiographer could compare the 1st and 2nd pictures and then report to Immigration accordingly. My daughter also has to see a specialist and he needs to report on the findings of her last x ray.
So we obviously need back from Immigration the original X rays sent to Immigration in Feb?
My daughter has managed to get a cancellation appointment to see the specialist which is this Friday, the 3rd August otherwise he was booked up until September which would of course be too late!
I have been telephoning and emailing Immigration every day since (2 weeks) but get no response from the email and the telephone line constantly tells me (no matter what time I ring!) ‘You have rung at our most busy time, please call later!.
Then on Friday I did get a response to my emails saying ‘Lillian Howe’ (our immigration officer) no longer works at Immigration New Zealand!’ Please call the Call Centre for further information!’
Aaahhhhh!
The only number I have for Wellington branch is 0508 558 855. Does anyone have a different number? Any advice as to what I am expected to do? I am completely amazed at the inefficiency of the Immigration Department and am out of ideas so please help!