sounds like main dealers can be just as dodgy as small local garages! 
Even worse Dazmond the whole things a racket, for a start 23 can take his van anywhere for a service as long as its to a
qualified mechanic but the dealers will fight you on it.
By law all you need to do to keep the warranty valid is to maintain the vehicle to a standard where by if you didn't it would
cause damage.
A new vehicle is guaranteed by consumer law but dealers use it as a way of taking us for a ride by charging over inflated prices
for servicing and replacement consumables.
The garage also has to be vat registered, and they have to use the "approved" service kit from the manufacturer.
I only know because I've just recently bought a 2014 Ford focus ST and looked into the servicing just recently.
It's first service since I've owned it is coming up, and I was going to be stung for close to £400 for basically oil and filters.
It's a rip off. I trust my local garage way more than a main dealer any day. All servicing by main dealers usually gets given to the apprentice who can only just tell there posterior from their elbow.
Don't do it damo. Go to a local garage if you know and trust one.