Submersible Pump stuck inside the borewell

Our Submersible pump installed with Ashirvad CPVC pipe has stuck inside borewell of 850 feet (approx).

Electrician told due to overheating of CPVC pipe in low water discharge, it might got melted in between and the pump with motor assemble got detached . The reason we guess is that the pump is being operated without Non return Valve for the past few days (3 weeks). Also the normal running time is 2 hours daily (1 hour in morning and 1 hour in evening). Further we have been informed while using submersible pumps at a depth of 850 feet, we should have tied rope along with the pump which we are not aware at the time of instalaltion. Kindly advise if there is any ways for taking out the motor and pump safely. With regards P.Karthiick