That is a wild response to give a customer. I'm surprised they are still in business if that's how they treat fairly reasonable customer requests.

If it's NBN, Aussie Broadband and Superloop/Exetel have good IPv6 support with prefix delegation giving you a /56.

What ISP is that? Name and shame. I'm Australian and want to know to avoid them.

Some of the larger Danish ISP has explained that they do not offer IPv6, because there's no demand. I very much doubt that they have any demand for IPv4 either, because most people don't know and don't care how the internet is delivered to them.

"I'm a software developer and I need it to do my job."

Even if it's not strictly true, that seems like a solid justification. Though obviously that won't work for the general public.