Clutch problem

Hi all, I posted on here about having no clutch and changed the master cylinder as suggested, worked fine for 3-4 days then nothing again, I managed to get it home by lifting clutch pedal with foot but this morning I can't get it into gear at all any suggestions. Thanks
P.s. I have a 2006 2.0 freelander 1 td4 adventurer.

It may need bleeding, or the slave could be playing up, I was told by a good clutch person that the master never really need changing on a TD4, if they do very rare, all that is needed is a good bleed through, therefore look towards the slave.

Is the pedal stying all the way down?
Is there any 'pressure' in it or is it just floppy?
Still sounds like air in the system.

There is some pressure but not enough to get it in gear,

I think the Flying Scotman is correct. The oil reservoir is difficult to fill anyway, but the union near to the Master cyclinder can be a sod to tighten properly too.

Sounds like still got air in it.

If you pump the pedal does it get better? Does it feel 'harder'?
If so, then its air.
If not then its a mechanical problem.

Open the master and see if there is any fluid left in it. The top just pulls off.