Sandbox merchant was removed

My Sandbox merchant stopped working yesterday, and I realized that the reason is that the merchant was removed from my account. I was using the default "Acme" merchant. I tried to add a new demo merchant, but every time I enter the demo merchant information in to the form and hit "Save", the form just re-renders itself with no errors and does not create the merchant.

What do I need to do to get a demo merchant back on my account so I can test my changes in a sandboxed environment?

Thanks!