I have spoken to these guys previously on behalf of a client who got suckered. Technically these guys are not breaking the law, but it is not a good financial deal. Plus once they get their hooks into you ("Hey, bro, we got a live one!") it is VERY hard to make them leave you alone.
In my case - I told them my client had signed a contract with me, I'm the publisher and I had already done a more lucrative deal for epublishing with another company.
They just tried calling me again - call dropped out within 2 seconds. They tried again within 60 seconds. Same story.
Before you deal with these guys, do your homework as a writer. Look at the other choices you have. Talk to other writers and writing groups. Don't get scammed or exploited!