Paying by Cash and Card in self service checkouts.

So if your shopping cost say €17, you would get €5 change from your €20 and if your shopping cost €18, you would get no change from your €20 ?
 
Say you use your card and pin to checkout and after 2 attempts it says invalid pin and 'total failure' how can I checkout by cash instead as the home screen is gone if you get my drift guys.
 
So if your shopping cost say €17, you would get €5 change from your €20 and if your shopping cost €18, you would get no change from your €20 ?
In D4? You have to surrender the keys for your Porsche to get a shopping trolley and the minimum shop is €100.