1/4 turn bath valve

[jules1234]

i recently fitting a bathroom with 1/4 turn taps, all was well then the cold tap failed to turn of completly, so i ordered a new valve that has the same problem and so did the 3rd valve tryed in the tap. i was told i was a straight swap of the new valve and all would be well but not.. can anyone help.
many thanks jules.

 

[jules1234]

maybe now reading more posts i can add more info, the inserts are for the rosini bathroom suite romm b&q. the replacement inserts came from a place in leeds called mayfair(my favourite magazine) the bow tie shaped disc seems to be in order but there is a spring washer on the hand grip(turny bit) but even popped off i cant get into the taps guts.