I've upgraded my S5 operating system to Lollipop, and lost all my contacts. How can I get them back?

[Jerry Burger]

I've upgraded my S5 operating system to lollipop, and lost all my contacts.

I re-imported the contacts from Gmail, but now it is only shown as a Whats-up connection. No cell numbers, birthdays etc. If I go to Whats-up, it displays the cell number, but I can't get it back to contacts. What am I missing?