Ask HN: What Can I Do About this Freelance Gig Gone Wrong?

I have been doing web freelance work for an small company for about a year. I took the job because I ran out of money trying to built my own thing. At first (during a two week trial period) I was getting paid by the hour a somehow decent rate per hour. After those first two weeks they told me they were impressed with my work and wanted to negotiate a deal but that they were not able to afford me. Basically the offered me to work for FREE and take an small amount of equity. I never saw a lot of future in the company (it could take years to see a return) plus I was broke and needed cash so I said not, I told them I was looking forward to get paid by the hour or monthly. After about a month of emailing back and fort we came to a terrible agreement. They would pay me $2000/month and give me 3% of the company (witch I couldn't care less because I knew I was going to be really difficult for me to ever see a return or for the company to be acquired) the deal was for an average of 3-4 hours/day 5 days a week. So I began working for the company and never cared about asking or signing anything related to that 3% of equity. The company founders have always been so demanding and I have always been spending more than 3-4 hours a day to get the work done and only getting paid $2000 a month. I'm a senior level web developer. I have been CTO of an start up, earned $100,000+/year, etc. Anyway, I kept the job knowing I wasn't getting anything fair in return because it helped me paying bills while working from home and also spending time on my own projects. About 2 months ago I was almost flat broke an took a job offer from an start up (also a remote gig) I'm making good money with that company and I have already out performed every single web developer they ever contracted with. I lost interest on the small company and I have been too busy with the new start up. I'm about 2 or 3 weeks behind schedule based on their deadlines (but also remember that I have done a LOT of work for free for them). They have been emailing me about status updates and I have not replied back in a week. What can I do?