Unable to pump water from the borewell. Need help

Hi, I have a borewell that was assured of 4" water at 300 feet total depth. I get the water for an hour and then it stops. So I stopped using it. However when I lift the pipes and pump, I hear the sound of flowing water down somewhere in the bore well. It is really like the noise of a pouring waterfall. Any advises on how I can stop that downpour and make it pump upwards? Thanks in advance.