Acceleration failure

I Drive A Toyota Camry 2010 SE.
When accelerating from a stop the vehicle will move at an acceleration of 2-3000 rpm and then hesitates to accelerate and returns to idle as I press more. The accelerator was pushed to the floor and the rpm remained at idle while the engine is still on. I have to stop and started the engine several times before the throttle picks up and responds and still does as aforementioned. The intermittent hesitation is very dangerous when trying to cross a busy intersection when the cross traffic is uncontrolled and especially during overtaking. The vehicle was taken to the dealership for the problem. The technician could not duplicate the condition. All my mechanics have failed to detect the problem. I would be really happy if you could help me out by figuring out my car issue as soon as possible. Thank you.