My Sony Xperia M appears to offer a feature that isn't publicised; during the second week of February it deletes all my contacts. It happened in 2014 and has happened again today 
.
Importing contacts has resulted in a handful of numbers being restored and I've been able to add contacts by going through text messages I've received recently but I can't locate the rest of my contacts.
On the 'Back up & restore' bit of the settings menu, the options to back up data and to automatically restore are both ticked and my googlemail account is listed as my backup account. However, I still can't work out how to retrieve the contacts that my phone had in it last night 
.
Any bright ideas?