There are many islands in the waters of the Grand Line, scattered thousands of nautical miles apart. And often deprived of general laws, traffickers make money from human trafficking. Either civilians who were unlucky enough to fall into the hands of dishonest traders, or pirates, whom they plan to resell with a huge wind-up from their original reward.

So you were unlucky enough to get into such a situation, but soon enough you were bought out by the Smoker himself.