I have found Telstra usually willing to do such things - I was hacked for a month once, guy ran me up to a $2000 bill!!! (I was on no throttling, unlimited, but with a specified agreed GB limit). Telstra agreed with me, and only made me pay $250 of the $2000 which I felt fair.
Same with Virgin with me. I had a faulty mobile that would send a message every 3 minutes to the same number for 12 days straight! My bill was something like $620 for one month. They were going to charge me the full amount. I asked for a complete transcript, and after discovering this, and sending me a copy, they completely waivered payment for the month, and sent me a new phone.
Westnet is my service provider now for 5 years. They are nothing short of brilliant in every single way. Never had an issue we could not resolve, and tech service is superb, always.
I cannot say anything positive about another big telco starting with O, so I won't say anything at all