Hello, I hope the following is of assistance.
If the engine was running previously to this but won't start now then I suspect that although you say you've primed the fuel filter this will be air in the fuel system.
These engines are notoriously difficult to bleed the fuel system on, you either need a vacuum brake bleeder attached to the return pipe from the injectors to the tank so you can pull fuel through the system or fit an inline priming pump in between the fuel filter supply and fuel filter, remove the fuel filter outlet pipe and pump the primer until diesel comes out then reconnect the pipe and pump the primer until it is difficult to pump then have an assistant try to start the car while the primer is pumped. Once the car is running leave it to idle for 5 minutes then remove the primer and reconnect the pipe. An example of the type of primer you need is http://www.ebay.co.uk/itm/Draper-Expert-Fuel-Line-Filter-Hand-Priming-Pump-Diesel-Engine-Tool-43986-Primer-/380756070544?pt=UK_Hand_Tools_Equipment&hash=item58a6d49090
It seems highly unlikely that a fault would have developed while the car was serviced.
I hope this helps but if I can assist further or if you have more questions regarding this let me know and I'll reply as soon as I'm able to.