Scaling model according to metric system


since I’m totally new to Blender and been using it just to create basic maze for my bachelor’s thesis simulation, I didn’t realize that the pillar I’ve created would be as large as it is

the pillar is supposed to be 2x2x4.8 cm, however it’s size is in meters

I’ve tried to scale it using the Transform tab in the main scene (idk how that’s called), but when I scale it, it actually breaks whole model (scaling wall this way was just fine, as there weren’t many ‘cuts’)

here’s the image without and with scaling (I’ve tried setting just the dimensions, not scale, but the end result was the same)

any suggestions on how I can scale this properly? or is there someone who’d scale this for me, if I’d provide blend file? (^_^)

edit: since it took moderators 2 days to approve this post, I meanwhile reached reddit community instead, where I got a solution in an hour