I have the same problem Trevor, but maybe it's better that way - I mean, if it was properly stirred, you'd have some vaguely chocolate-tasting water for 100% of the cup. Perhaps the real problem is that they don't provide enough chocolate powder. If you cannot get a response from the vending machine company, complain to Trading Standards (http://www.tradingstandards.gov.uk/) describing the situation (twist the facts a little, like saying they source their cocoa beans from small children in South America who get 5p a week). Hopefully you should get a response from the company, saying "We will lower our prices" or "We will add more chocolate" or "No you can't", but because the customer support department is in India now, they misspell "can't" and even forget to put an apostophe in. I mean, how can you put a 'u' in "can't"? Ridiculous.
Remember kiddies, don't follow your Uncle Muggus's example and scull and entire 1 litre bottle of Lemon Lime surup cordial in one go when drunk. Being drunk is one thing, ODing on sugar whilst drunk leads to bad BAD things.
Conclusion: Sugar is bad unless mixed with yeast and fermented.