Do here goes.

I sent my focus 1.8 tdci into the garage for a water and thermostat to be replaced the garage rang me to say that the timing belt went around the water pump and do I want the timing belt kit to be replaced which I agreed. Upon picking the car up it had a slight ticking noise and the car seem to have loads of power.

About 4 or 5 days later the vehicle broke down then the garage and told me that the the chain had snapped and the crank shaft had seized. Apparently the garage didnt release that the car has a timing chain aswel.

 

Would a incorrect timing belt make the crank shaft and timing belt slip etc 

 

Advice is much appreciated 

On these engines, there is a twin (Gemini) chain which runs between the crankshaft and the injector pump.
The cam belt, in turn, runs from a pulley on the injector pump up to the camshaft.

Changing the cam belt does not require the chain to be touched at all.
Its a bit of a mystery as to how the chain could have been affected in such a way.

If the car was build in 2008 there is a huge chance that the engine does not have a timing chain but a wetbelt. In 2008 Ford stopped using the bulletproof timing chain on the 1.8 TDCI and replaced it with a much more delicate wetbelt. At the time this and a few other changes were necessary to (barely) meet the emission regulations. This way Ford was able to use the already outdated 1.8 TDCI a few years longer.

If the engine does indeed have a wetbelt it should have already been replaced. The prescribed changing interval is 10 Years / 125K Miles (whichever comes first).