Octavia oil overfilling

I recently changed the oil on my Skoda Octavia 1.4-litre 90 kW TSI. The book says to use 3.6 litres, but the oil level was way, way above the full level on the dipstick after only 3 litres had been put in. I'm certain the sump was empty. The owner's book is full of warnings about damage to the catalytic converter if driven with too much oil. Your thoughts please.