Who did the electrical installation?
If the neutral is broken, there will be no return path for the current. For a single phase circuit, nothing can work without a neutral. for a balanced three phase load, the presence or absence of the neutral does not matter.
I have no idea about the internal details of the chargers but if it has to deliver meaningful energy in a reasonable time period, the source should be more than 10kW and it shall ask for three phase supply.
My flat does not have three phase supply and if I have to install a EV charging station, I need to apply for another power connection that will be independent of my home connection. Three phase electrical connections at 440VAC comes with a distribution power transformer that is installed at the customer premises (sometimes they are also pole mounted but that depends). You usually draw the neutral from there.