2012 Citroen DS3 can't view trip computer information

So pressing the end of the stalk should go through the trip computer but it just changes the radio to aux and back again. I see the mileage range on the screen and I press the end button on stalk to go to mpg or average speed etc but it just turns the radio to aux mode and back again. I've tried every button & read the handbook but no joy. Anyone??