Why is my WhatsApp not updating my Contacts?

[Smith_Adam]

I have received messages from non-contacts on my WhatsApp and when I try to save the contact and then Update WhatsApp, the contact is not saved. I even tried deleting an existing contact, upon which WhatsApp removes it from my client list, and when I want to re-add it, the number simply saves on my phone and does not update on WhatsApp. I have tried to save the number with and without area codes, on the device and sim card, but still no update. I have a Samsung Galaxy S3 Kernel Version 3.0.31-2454463 and all apps and software (currently available) is updated. Could anyone assist?