I know nothing about cars but I had a similar problem and it was the immobiliser, I purchased an immobiliser override gadget online and it sorted the problem. Or try and reset the immobiliser, good luck.
Thank you all for your answers. It looks as though the battery in the car has gone belly-up. There's not enough power in it to make the radio work! Let alone the car locks & ignition.
Carrust, at times the battery will give you warnings! " Very slow turning over" will start very quick, check your dash, do you have a very faint Red light showing? If yes, Alternator, Is your battery of the Top up type ( YES ) they still use them, check that the battery cell are topped up with water, get the battery checked before you jump and buy a new one.
Gorrit sorted. Auto electrician found that the regulator in alternator was stuck in the open position, thus draining the battery. So, new battery & alternator are required....sob...