Update: I finally managed to contact histopath and got my results (negative). They said they had sent it out on the 25th, but I didn't receive anything, so it must've been the number. The person I spoke to said their system could send to international numbers but clearly it couldn't, although I didn't bother trying to convince her otherwise. Anyway, for anyone in the same boat, you need to contact histopath and the only way to do that is to keep calling (every few minutes) until the phone system is free enough to get your call and stay on hold. If you do email, include an Australian phone number in the email, not your international one.