The reason that there are 4 copies of the texture is that the UV coordinates for the texture specify that. It does not matter what size the actual texture image is, the UV coordinates specify a relative position in the image, what percent across or up and down, to apply to a face.
You can resize the texture using the UV tool in the Point editor.
1. First select only the faces with the texture you want to rescale.
2. Then click on the UV button and
3. click Yes in the dialog to enable texture UV generation for the object.
4. Click drag in the middle of the big yellow circle on the screen with the MIDDLE mouse button to rescale the texture. Use the RIGHT mouse button to move it if it's off center.
