I am already in gear and driving and it just revs. My foot is not touching the clutch. I've been driving a manual for 20+ years, never destroyed a clutch. RS Motorsports serviced it not too long ago and all was good. So, no idea what's going on.
What does the pedal feel like when you depress it ?
Does it feel like it is depressing the pressure plate ?
Is there any free play at the top, before it engages the pressure plate ?
Does the pedal go to the floor and stay there ?
If so, can you pump it up ?
These are all necessary questions to diagnose whether it's the master cylinder, or the pressure plate and disc causing the slippage.