r reg peughot 306tdi...pump problem!!please help:(?

hi,,,my lil peughot has been running great up until the other week,,it turned over but was nt firing :( i called out break down and they said that theres diesel going into the pump but nothing is coming out??
took it to a garage and they said that it cud be an imobolizer problem? (i have a key fob imobolizer not a keypad one)
anyways the garage said that they have to take of the imobolizer of the pump and it shud be ok,,,the only problem is they want 5oopound plus to do it!!?
please help!! :(
really look forward to getting any advice
thanku
chris