You cannot be hypnotized to do anything against your will. If you are hypnotized to do something which violates your deeply held values you will not do it.
However, there are "exceptions." Not really true exceptions to the rule, but just ways "around" it. It is true that someone cannot be hypnotized to do something against his will, but most people don't have a specific will or intent or even strong towards or away from values for most contexts. If you are selling something, as long as it is something reasonable, most people will not have a specific intent not to buy. Using your skills to get someone to commit a crime will probably not work on a normal person but a criminal would only object if he thinks he will get caught.
Values can also be changed using NLP, just as they can be changed naturally but only quicker. How many people know kids who were well-behaved before they started hanging out with kids with very different value systems or people who changed their behavior due to a religious conversion?
Hypnosis is nothing like how urban legends portray it, but it is also true that certain "rules" can be "bent."
