How do I recover my contacts after a factory reset & format?

My Samsung SIII Mini I8190 slowed down as it was overloaded (RAM usage 92%!) with pics and videos - my wife's doing! (S'true!) I connected the phone to my laptop (hp ProBook 4310s Intel Core2 running Windows 7 Professional) which has 52,6 Gb free space. I created a folder on the C drive called SAMSUNG SIII Backup. I then opened the phone and copied the folders and files to said backup folder on the notebook. So far, so good. I then executed a factory reset on the phone. It's response time was still slow so I reformatted the phone as a "Mass Storage Device" and reinstalled the drivers from Windows Update. I have removed (into a dedicated PC folder) all of the offending video & photo material both from the camera as well as from WhatApp so they are safe and sound albeit that the folders on the phone are now empty. This after I sent the deleted folders (sans contents) back to the phone. I have recreated a new Samsung Account as well as a new Google (gmail) account and cannot get any joy except for making and receiving calls and SMS. Apps will not install. FB; WhatsApp; Google Play, etc . . . And, lastly, I cannot find the contacts folder to restore that. I'm now in the dwang! Please help me ;-( PeterG Cape Town, South Africa