There you don't go. There's not gonna be 800k handhelds on the shelves when total sales have only been 3.5M. Scaling that up would mean 1/4th of every PS4 or Xbone shipped would be in the stores. Those consoles may have 1-1.5  (2M consoles max in the holidays) in the channel considering the volume in which they sell, Vita is obviously not close to that.

It's been undertracked for quite some time... hopefully they get the numbers more accurate

Hopefully.

is not possible to talk to ioi and try to correct the figures , and thus increase psvitas sold so far ?

Shipped and sold.

There is a reason why Sony don't support Vita anymore.

If Vita is undertracked than the others are also undertracked.

But wasn't Vita sold out in the US for much of 2014?

We all know the figures don't tally. But there's nothing ioi can do while they don't know where the systems have been sold.

Why are the two mutually exclusive?

i guess it's undertracked by 400-500k...even adding those,vita is selling badly in the western countries and sony stopped supporting it too early.
This device deserves at least 3/4 good first-part games each year