The only time I've seen this error occur is when the Symfony command is being executed in the wrong place.
Since Symfony is a build component of AtoM, all command-line tasks in AtoM (i.e. all those prefaced by php symfony) need to be run from AtoM's root installation directory. If you've followed our recommended installation instructions, this is typically /usr/share/nginx/atom.
Ask your IT team to change directories first, and I suspect the command will run. If not, please let us know!