Good morning sorry to hear your having issues with your camera.
What happens when you set the knob on the top of the camera to the "A" position, does an A appear in red the top left hand corner on the LCD display?
So the control wheel is set to "A", but you dont see the A on the top right hand corner of the display.
This certainly sounds like a software issue on the camera, I would suggest you take it to a service centre,
If you provide me your postcode I can find the nearest repair centre, so you can arrange its repair, as I dont think this is a consumer level fix.
That sounds like the best option if your not near a big city, and its still under the Amazon warranty.