Note to white605: "Fillup your page with carriage returns to the next page"
Aaaacckkkkk!!! No, no. That is bad advice. It is never a good idea to put in ANY "empty" paragraphs (carriage returns) to develop space. Never. Nor is there any need to do so.
I have received the file from the OP, and they did that. Filled the page with a bunch of paragraphs. I removed all of them, made the desired paragraph centered vertically (and horizontal), and....it works precisely as I have been stating it does. Even adding a Section break.
The OP has this centered text bordered (above and below), but that was resolved - as just about all format issues are - by defining the paragraph as a properly constructed Style.
In any case, what has been stated all along still holds.
Center the paragraph vertically on the page using Page Setup, centered horizontally using Centered as an attribute of the style.
Done.
While the OP stated "reply on forum" - and I have now done so - I also returned the file to the OP, with my changes, in the hope that it will demonstrate that it works just like we have been saying it works.
Gerry