Issue on drawing a network design

Hello,

I have a question regarding the drawing of a design I'm planning. I'm using Visio but I'm open to switch if the alternative is better.

I need to draw the physical part of the network, with every component. I found the stencils for almost all my hardware but I'm stuck to a stupid task. I cannot resize the rack altogether to make it cover most of the drawing area (which is an A4). I get to resize the containing part of the rack but all the rails inside stay their dimension.

Here a pic of what I mean.

How can I solve that? I'm sure it's a dumb question but it's three hours I'm trying to make it work.