I am not trying to come off rude, but it really is your responsibility to ask the questions when someone is providing you a service. No matter what the book says, your idea of a "service" is different than what the dealer considers as a "service". Don't blame them for not doing something you consider important that they don't. We see this all the time in the auto industry. Customers do not ask and then when they don't receive what they expected, the shop is blamed for it. We educate our customers to ask the hard questions, demand details and have a record of what was done and offered. When we do a used car pre-purchase inspection we go though this in detail and it amazes me how many people are unaware that they can actually ask questions.
Dealers in the UK, and VW dealers have a particular reputation for this, would never miss an opportunity to get the customer to spend more money with them. Everyone in service at dealerships is targeted and bonused on this.
Few customers understand service schedules and VW don't help themselves as the schedule changes at year 4 - for the first 3 years here the cars get little more than an oil change and some checks. The schedule and work required is also different depending on whether the car is on fixed interval or variable servicing.
For instance, I've been told air conditioning service is "mandatory" at 2 years, yet try and get the dealers to do the 3rd year brake fluid change as part of the initial discounted service contract and they'll refuse and make you pay extra, saying it's not included as it's a "customer option".