where do i buy the hard clear tubing control rods run in new plane had wrong size come in it have to replace it

Any good hobby shop, whether it i s a local physical store or online will have nylon push rods. If you don;t have a place in your area, try www.towerhobbies.com. Click on "aircraft accessories" and you'll find all sorts of stuff listed including various types of pushrods and linkage.