Fake Muscle Milk?

I bought a package of Cytosport Muscle Milk powder from discount-supplements.co.uk. Even though it was a very low price with free delivery (£20.75), I've always thought the website had a good reputation. Amazon also had the price near £21. When it arrived, of course first thing I checked was the best before date, which was August 2013, so I thought that was why they could sell it so cheap. Then I noticed the package I received had several differences to the pictures displayed on cytosport.com. Funnily enough, discount-supplements.co.uk have not updated their pictures and still display the old packaging.

Four main differences are
- "Muscle Milk Protein" instead of "Muscle Milk"
- "High Protein Drink Mix" instead of "Nature's Ultimate Lean Muscle Protein"
- The red and white "genuine" banner starts on the left side of the U, rather than the middle
- "Cookies Flavour" instead of "Cookies N Creme"

I overlooked these differences, thinking they could just be differences between UK and USA packaging. However, after finding that it tastes UNBELIEVABLY HORRIBLE whether made with milk, or water, or twice the amount of recommended water (to try and reduce the taste), I am very suspicious of what this powder actually is...