Hello, my name is XXXXX XXXXX I will try help you with this.
What you have been told is correct about being unable to adjust the electronic brake.
Do you think it has been sticking?
Has the clutch been slipping or has it now lost all drive?
It does sound like it is slipping.
This is going to be difficult to prove it wasn't your fault or style of driving that caused it.
What you can do is ask to inspect the parts when they are reomoved. If the drive plate is worn then that is probably your fault they will say. If the drive plate is servicable then the pressure plate is likely to be the cause. This would then be a mechanical failure and so should be covered under warranty. The other thing to look for is contamination of the drive plate. If oil has got onto it then again this is mechanical failure and should be covered.
I thought you said car was 18 months and with 30,000 miles on it?
Make sure also you are not getting mixed up with clutch/flywheel problems on diesel cars due to the dual mass flywheel.