There is no way to rotate just text or really any individual object within Acrobat.
The problem with your PDF is that is rotated 180 degrees. They've been scanned in "upside-down" and then rotated to look correct. Since the PDF is essentially a container for an image, Acrobat doesn't know that it's an upside-down image.
All it knows is that the page has been turned on it's head, so when you insert text, it "rightly" assumes you want the text upside down as well.
Acrobat does allow images to be edited with a program such as Photoshop, and will re-insert the edited image into the page.
So if you have an image manipulation program, you can select (in your case) the "page" with the TouchUp Object tool, then right-click and select "Edit Image". Your default imaging program will open, with the extracted image. Rotate it 180 degrees, save it, and it will update in Acrobat.
Then you can "un-rotate" the Page in Acrobat, and re-insert your text.
Thomas D. Greer