Why can I not see my contact, logs?

A

AC Question

I have a Samsung S4. I have run the Aug update.
I am not technical and need help.
My contacts do not appear "Contact list is being Updated". Same when I check my call logs. It also redirects me to ads and apps every now and again - this would suggest a virus, but when I run virus checks, nothing appears. The phone also takes the notion to reboot itself.
I have gone down the troubleshoot path and have already Cleared data and Cache.
Please help - before I throw it out the window!! Grrrrr!!!!