Legitimately asking for a friend here, I'm not personally in this situation.
Scenario: De facto couple for ~10 years. Partner A has maintained the joint savings account in their name only, which both partners contributed to. The relationship ended some time ago, but they have only recently separated. Partner B now wants their share of the joint savings but Partner A is refusing. It's around $10-15k
What can Partner B do in this situation, if anything? QLD if it makes a difference. Partner B is well aware that they made a big error by not insisting on a joint bank account or something in both names rather than just Partner A's.
Tl;dr: De facto couple broke up, one partner maintained joint savings in their name. Other partner now wants their share but the partner who held the savings is refusing.