Unsafe pedestrian crossing light

In this extremely busy pedestrian crossing (grosvenor gardens) the traffic light for vehicles turns from red to amber halfway through the green light for pedestrians whilst crossing. Due to high traffic congestion, EVERYTIME, the vehicles WILL NOT RESPECT the fact that pedestrians are still crossing. We all are fed up of risking our lives every time we cross in this dangerous crossing. Furthermore, this crossing is in a blind spot for vehicles and pedestrians to visualise each-other as it is located in a turn off Buckingham Palace Road. Us, residents from this area are aware of this issue, but as this crossing is used by tourist constantly who are unaware of it, it makes the problem even worse. We would like this lights to remain red for the traffic flow until it will turn red again for the pedestrians.