SimpleBank tried to do this in the US, and ended up with a lackluster acquisition by BBVA [1]. Standard Treasury also tried this at the institution level, and also ended up with a poor acqui-hire outcome [2]. Without being able to be a technology company first, and a financial institution second, these efforts are doomed to fail. I hate to say it, but the best companies to attack this are Amazon, Google, and Walmart (companies that are either Agile or ruthlessly efficient).
With that said, I feel your pain. I work in security for a financial utility in the US, and some days, its impossible to get anything done. Use opportunities like this to sharpen your bureaucracy hacking skills (and the money isn't bad either). Failures are only lessons you don't learn from.
[1] https://en.wikipedia.org/wiki/Simple_(bank)
[2] https://www.bizjournals.com/sanjose/blog/techflash/2015/08/s...
> ridiculously crazy per-job pricing models where the job was never actually completed correctly and would often be charged multiple times to fix it
IMO it indicates something about power and incentives, where somebody in the company -- possibly in sales -- benefits from being able to arbitrary rewrite or ignore rules.
They have enough political clout that supposedly standardized systems must accommodate their fundamentally unpredictable exceptions, leading to software that is fragile or insane.