Phone interpreter is available 24/7.

I'm a local doctor in Sydney. You can always have the phone interpreter 24/7. I had treated many non-English speaking patients in hospital, such as in ED. Usually the doctor can get on the phone interpreter( free for patient, the hospital pay for that) and had consultation with them. Ideally when you make the booking you should mention that you need an interpreter on site. But I don't think it is a big issue anyway.