This 2000rpm thingy is the fail safe mode of the engine management system. The idea behind it is that it should allow you to limp home if there is a problem.
Usually the fault lies in the accelerator potentiometers ( two included ).
Is the car still under warranty ?
A call to
Renault Customer Services
should put your dealership under pressure to correct this problem as it is a common problem.
( computer ) will crash causing the same error ( which sounds like your problem. Have the dealer reset your