All Praise is for Allah.
There is nothing wrong in selling raw material as long as it is used to make something permissible and not used to make something that is forbidden. As far as the manufacturers deception is concerned: he should be advised and stopped from his evil deed. You will not earn any sin for what he does in manufacturing. However, if you stop dealing with him and find business with honest and truthful manufacturers, that is better and safer.
Allah knows best.