Info 2 [Q] Contacts linking

Hello,
I have an Asus Fonepad 7 with android 4.4.2 .....the ting is when i go to contacts and pick any contact>menu>link and then i choose whom contact i want to link the first one to (whether it's a facebook contact or a whatsapp one) then after i press the Done button nothing happens ! ...and if i go to same contacts and try to link it again I see the it's not linked to any other contact ! .........what should i do ?