oil change for VW 2016 Beetle Turbo

Can you tell me if there is a such thing called a "crush cap" on a VW Beetle's
oil filter that may need to be changed to prevent a slow leak?  I took my
daughters car into our local dealer because her coolant light was on.  
Nothing was found wrong with that but they checked her oil and they told me
there was a slow leak and that it was the crush cap that wasn't replaced by
the last person who did her oil change.  I went ahead and had them remedy
the situation and change her oil and replace this so called cap.  I was later
told that no such thing exists and that they lied to me about this.  Probably
because I am a woman and they saw me coming.  Can you please settle my
mind and let me know if in fact this exists or if I need to go back to them and
question what they did for an extra $50 along with her oil change.  Thanks.