I, too, am sure they won't rip you off.. Send them an email stating what you purchased, with your contact info, and your concerns. They probably want to know your weight so they can recommend a good dose for you. As I and others have said, 2g of TA isn't likely going to be enough for a flood, but you can still order and do whatever you want. I wouldn't worry about them ripping you off, however, as they do care about their reputation very much.
Unless you weigh like 50 lbs, 2g of TA isn't gonna cut it, for a full relief flood dose.. I am betting it's only around 50% pure alkaloids, and maybe 30% of that is ibogaine. That is my guess, anyways, from the Iboga World TA I have eaten..