Anybody able to offer advice?

We've got a Whirlpool Fridge Freezer (double door, upright, american style).
The water filter registered as needing replacement on Christmas Eve, didn't
get round to it until this week, got 3 filters from Whirlpool (£78) inserted
one, and ran off 14 litres as per manual, got a bit of air through as it
said we should, but the LED disply on the door says the filter needs
replacing. I've had it out and put back in again several times, turned
power supply off for about ten minutes hoping it will reset.
Whirlpool's servive line isn't open this morning, anybody know what the
problem is?

regards

IanC