Cant update

Dear Sir/Madam,

My problem seems to be the fact that i cant update. everytime i press update to 4.5, it says succesfully. but shows me 4.2.2 instead.

So when i refresh my page it says again. Please update to 4.5?

It is not for my own site., But for my boss! so it is really important!
Anyone had the same problem? and solved it? I really would like to know!

Greetings,
Lupo Kunst