How to change button design and its position on Contact page?

Hi,

I have an issue with buttons design on the Contact page.
I am trying to make them smaller and aligned in 2 columns instead of one.
In Ui file I moved the buttons on desirable positions, but when test running it is still shown in order one below another.

I was changing some of parameters such as f="L" and af={0,-10} (made them f="R", af={0,10), but it didn't solve the issue.

By the way, what do "f" and "af" parameters control?