Thought I was getting a good price for a thorough service, but after checking the invoice for whats been done, i'm not so sure!!
It would probably cost you that for just an oil and filter change at some main dealers, so no I dont think you have been ripped off.
What you have to remember is that okay.... maybe the bits cost £50, and the other £100 is labour.... but its not like that £100 just goes in the blokes pocket for wages.... deduct some for renting and running a business premises, the costs of disposing of trade waste and used oil, and then knock 22%-40% off whats left for tax and I doubt he is left with very much!
If I was using a non-main dealer garage to do work on such a new motor, I would want it clearly showing on the invoice that genuine stuff was used such as part numbers and parts prices, incase you have any waranty problems, and also looks a bit better for when you come to sell the car.
The only way you will get it done cheaper than what you paid, is if you do it yourself.