Bike Description

I locked my bike up under the fly over at Anglia Square in Norwich next to the burger van on the 16/2/15.  I left my bike at around 9.55am and returned at 11.45am and found it missing. Whoever did it had cut the lock and left me a battered Claud butler bike in its place.   It's a mountain bike with a slight rip to one side of the seat. It has front and rear plastic mudguards coloured black.  It also has a back light and a standard Claud Butler bell affixed to it. It also has a two and a half inch piece missing from one of the plastic pedals which I still have. Please help me find it.