Fuel pump can often go west if you regularly run the tank right down, this happened on a Punto turbo diesel at about 50k I used to own and play fuel light bingo with (49.2 litres was my best fill...it had a 49 litre tank!).
I wouldn't blame Citroen - the part will be a generic pump (Bosch etc.) that's in all sorts of cars around the world.
Yes, it is a sure fire way as all the residual 'cack' on the bottom of the tank gets drawn through the pump, eventually killing it. My dealer replaced it under warranty but did suggest I try to leave about a gallon in the tank as a minimum so must have seen from the condition; I now refil at the first opportunity after the light comes on in my A2 (36 litres in a 42 litre tank) and I never get more than 50 litres in the DS4.