Unable to backup via google backup, despite checking backup & restore options

[Dhruv Laroia]

I am using a Sony Xperia M4Aqua Dual. My phone resetted itself (dont ask!) and now im left without any contacts or apps. When i started up by phone again the first time, Google did not restore my apps or any other data, despite me having checked the 'backup and restore' options previously.
Can you please help to suggest how i can get my data back? Most important is to get my contacts back, the rest i can manage.