Ouch,..maybe they didn't tighten up a pulley or something and the belt came off and water pump stopped running. They should definitely have to fix it...How long ago did you get the work done?
The water pump runs off of the cam belt, if the cam belt comes off of the water pump the belt will go very loose and the engine will stop with multiple bent valves before it gets chance to overheat.
I think the water pump impellor has failed personally and they will need to replace the water pump for free, then fully test the cooling system (pressure test) to see if any admage other damage has resulted due to overheating.
Then again a failed water pump doesn't normally give derv noise simptoms
this could be loose turbo mounting bolts, blowing boost pipes or an exhaust
problem as the engine was moved about to do the original work.
I trust that they fitted the uprated type of pump with a metal impellor and not the crappy plastic type?