I bought my 1400 TSi in 2013 and after a year decided to ask when the cam belt needed changing, idiot dealer said 30,000 miles or 3 years. Thought this was stupid since they would never sell as asingle car to a fleet if this was true.
So I emailed Seat Customer Services who came abck with the following reply
"I am delighted to confirm that on your SEAT Leon, we recommend the cam belt is first checked at 60,000 miles, and every 20,000 miles thereafter. If there is no damage at these points the cambelt will not need changing. If the belt is not changed, regardless of condition, it must be replaced at 120,000 miles or when the vehicle is 5 years old, whichever comes first."
To me that seemed sensible and straightforward. But I have no ide if it applies to other Leon engines.