Help! New foundation not lasting long!

[CountryRoadTakeMeHome]

Have posted about my fabulous new foundation before!

Trawled this site for advice (with many thanks )Have gone for Chanel Vitalumiere Aqua compact and it's beautiful!

But.... I only purchased at £40 from boots less than 2 weeks ago and have already used enough to see the bottom (middle bit) of the compact . I use once a day and touch up 4 of those days due to the nature of my work (I get wet!). I do not cake it on even though I'm (cough) from good ol' Essex

How long does yours last?...