Thats a load of BS. Can't be trimmed? ANY plane can be trimmed. It's whether or not the trim is effective that's the question.

What is this "tiger shark" plane you bought? Do you have pictures or a link to a website? We've gotta see what we're dealing with.

Are there sliders next to the control sticks on the transmitter? Those are trim tabs. For the left-right one, you slide it right if the plane goes left.