From the sounds of this you have the child lock turned on thats why its not doing anything. This is a simple fix.
Look at the row of button on the control panel.
Under 2 of them you will see a picture of a padlock and 2 arrows pointing to the buttons.
Press and hold the 2 buttons at the same time for several seconds and this will turn the child lock off from there.
Try that and see how it goes and let me know.
Nice one, Thought that would sort it.
If you could remember to rate the answer that would be great.