[dragonwriter]

The DMCA takedown provisions are a safe harbor against legal liability -- compliance protects a host against legal liability they would otherwise have to a copyright holder for copyright violations. Implicitly, they are backed by the threat that, if the receiver fails to comply, they will be subject to a lawsuit for copyright infringement.

If you are sending DMCA takedown notices and they are being brushed off, you probably are at the point where you need to talk to a lawyer

[swandive]

Ugh. We're a very small company, and we don't exactly have tons of money to spend on a lawyer at this point.

[dragonwriter]

Sure, you have limited resources you can expend on legal services -- but you presumably also want the piracy to stop. A consultation -- which shouldn't be too expensive -- will give you a better idea of what your options are and what it would take to pursue them, from which you can evaluate what it is worth doing given the value of the content involved.