That's a very good question! But the answer is simple, I'd just declare myself an Admiral and keep them both. ;)
Especially selling your soul away like that? And going in the first place, thinking that that witch would help her for free? Nothing's ever free, little mermaid, and you can't just go rushing in thinking you'll make anyone fall in love with you in three days.
Though I despite feeling as if I'm not free, so I won't scold her too harshly for wanting to get away from that oppressive daddy of hers. But still? He danced on a ship and played a flute and you're in love with him just like that? So silly.