2015 Ford Fiesta car won't start

Car purchased in Feb 2020 and to date the car has failed to start on four separate occasions. 1st - Boot and passenger door would not open, when key put in drivers door to get into the car. Immediately after when
putting the key in the ignition, car was completed dead and would not turn on. Dashboard completely dead.
AA recovery called to attend, but while waiting for AA to arrive after about 15 minutes the cars 'electrics' turned themselves back on. When AA recovery tested the car battery it was noted 'battery needs re-charging'. Car turned back on after about 30 minutes. AA suggested to attend mains garage to investigate. Took car to Kwik Fit for diagnostic test but no fault found (battery, starter motor and alternator all ok).

The following day car again failed to start. While idle the 'car electrics started resetting' and I could hear a ticking sound behind the dashboard then after about 15 minutes, car would then re-start. Returned to Kwik Fit Colindale and again mechanics could find no fault. The following day repeat after turning on the car I noticed that the clock and date had re-set itself to 2014. Went back to Kwik Fit but again no errors noted.

Two weeks later car failed to lock and when I tried to re-start the car it wouldn't start again. This time after slamming the drivers door the 'dashboard lights came on' and then after turning the ignition car re-start.

A week later car failed to start again and is not starting at all now. I slammed the door to see if it did the trick again- and enough power returned to lock the passenger door but then all electrics failed and wont start at all.

Please help, thanks!