Unfortunately, been there, done that!
In 2020 I was updating my details with every business after changing my birth certificate, and most went ok, until I got my online bank. I filled in the form, and their reply was that they needed more information. They wanted my doctor to provide details of my medical records. I refused and said they could only ask for the standard 100 point ID questions banks use to start new accounts. I got a reply that the extra information was required by the Privacy Act.
I immediately demanded to talk to a manager, and informed them that asking for more information than a cis person was discrimination under the Sex Discrimination Act, that banks do not ever have access to medical records, and that the Privacy Act claim constituted fraud. They admitted they didn't have policies to cover Trans people, and were limited by the software in their systems. I demanded they do whatever was needed to update their policies and systems, and they replies that they were a global bank and couldn't change just for a small community.
So I took my complaint to the Australian Human Rights Commission, and they had meetings with this online bank, advising them that the charges I mentioned were justified and they were exposed. The online bank responded that they had informally made policies to make it easy for trans people to update their details, and had accepted a quote of AU$2.7 million to update their software to facilitate the changes, but it would take them months to complete it. I checked with them every 3 months until it was completed.
I mentioned to the AHRC that the other banks had similar illegal policies, but they told me they could only act on individual cases. My other bank was very good, updating my details and giving me a direct contact in case I encountered any problems. I actually think the customer service guy I first spoke to at the online bank was a transphobe, as when it was elevated to management they apologised and seemed to be trying to help.
It was a bit of work, but I did feel I had done something for our community.
Hugs,
Allie