Holes and Stains in Shower

We installed an Oxygenics shower head. Really liked the shower head. I tried mounting it were the old shower was. Forget it. Has to have wood behind and it is to low.it. So I moved it and now I got two problems. I have to fill three holes somehow. Does anybody have any ideas how to do that? Also the holder, designed for the Oxygenics shower head, turned the shower wall brown behind it. So now I have a brown spot on the shower wall and three holes. Tried cleaning with solvent lightly but it is still there. Anybody got any ideas on how to clean the stain off?

I used the same mounting holes in the top of the new bracket, but i moved the hose support to the left and that left me with two holes behind the new bracket. I put some caulk on the white srews that the old mount used and screwed them in the two holes. They are behind the new bracket so not easily seen. havent had a problem yet.
As for the stain i can only think of a rust remover or a harsh cleaner like sray nine.

Thank you. Putting screws in is a great idea. The hose support is a pain. I have thought about getting rid of it. It does not seem to be needed with the new shower head.

I was able to use the existing bracket when I installed the oxygenic head. Didn't have to change anything. I have now removed the oxygenic head and will try the Camco head this spring. Some have said it seemed to work better for regulating the cold water bursts. We will see.

No trouble with cold water just to tall and they mounted the original shower head to low. Now the hose support is a pain.