can it be fixed?

hi,i have a 51 plate 2.0l hdi Picasso.had the car 5yrs or so.problem one was I only had 60% of the bsi unit working on car,dealer quoted £550 could not afford it to have this done.still be able to drive but when you turned it over the hazard lights would flash,just pressed warning light on dashboard that solved it.drives normal.i was driving one day last week and had immobiliser flash up on dashboard and the car slowed to a stand still,no fuel came through, but my tank was full?me thinking it might be fuel pump took to a local garage,he did diagnostic low pressure in fuel tank,now its had new fuel switch the pumps have been checked,battery would only charged up 20%,new battery in,still finding fault,bloke says he is having a man coming out today to reprogramme the car?hope this works.he was talking to a man from citreon and he said scrap it?any points you could give me.thanks.