I have a Galaxy S5 Mini.
Yesterday nearly all of my contacts disappeared. I now have only 8 random ones.
I did a factory reset this morning after exhausting all other possibilities. No I hadnt backed it up before this happened. Thought computer would just re-sync and it would be ok.
My phone was set up to sync with computer. It says it has synced contacts but it hasn't!
Using Virgin own email client as cant get outlook to run on my computer so how can I get them to talk to each other ? Even plugged it in to computer and they dont talk!
Don't know much about sync with a computer as all my stuff is cloud based
Are you using this http://www.samsung.com/in/support/usefulsoftware/KIES/