Is transformer really neede?

Our business is in a remote area we are only using a generator for our power requirements and it is 440 volts.Problem is the generator was installed near our plant it is 440Volts based on the tester but in our warehouse the voltage drop to 380 volts and it damaged our domestic appliances ther since we only put one line to ground just to have a 220 volts.Are we really need to buy a step-up transformer to be install at our warehouse?