Ask HN: Corporate bully trying to take the code I wrote?

I was approached by a couple of business guys back in december, they wanted to create a company. So I went along with it, created the software - but insisted on an agreement be made. This never happened, I ended up writing a lot of code, and no agreement was ever formulated.

I got sick of it, and bailed. Now they're telling me that I need to give them the code.

I live in Canada, and no idea how to reply. I donn't have resources or time to put towards this argument.

What should I do? Am I legally bound to send them the code?