Vauxhall Astra auto throttle problem

I have had the car for about 5 years without any serious problems. It has been regularly serviced by the Vauxhall garage I purchased it from.
Today I had to reverse into a parking area, put it into reverse and as soon as I touched the accelerator pedal, the revs immediately increased and caused a 'high' speed reverse. This caused serious damage to the car.
Has anyone had similar experiences with the throttle sticking and has there been a problem which Vauxhall has had to deal with in the past?