Radio blackout

Hi I would be most grateful if somebody could help I have a 2013 C-max and the radio/infotainment system just randomly shuts off. most of the time when its in one hour mode when the ignition is off, more rarely when the engines running, most often it gives up when I'm on a bluetooth call. very distressing it is too having to scramble around the car trying to find the phone in a panic. 

After a random amount of time the radio will start again when the car is re started usually within a day or two. but recently it turned off for a month and a half, i tried pulling all the fuses, eventually i tired of the situation and took the dash apart and pulled the plug out of the back of the radio unit and straight away plugged it in again and it worked. 

Has anybody any ideas why? It would be good to feel confident i can put the dashboard back together.