If you have lost faith in your hosting company to provide you both the support and service that you believe you deserve, then you should move to a new host. There's no point in delaying the enevidable. If they tell you one thing, and then contradict themselves, you should point it out to them. It could have been a typo (like forgetting to include the word "NOT" or something).
If you are getting contradicting stories from various reps, then that needs to be addressed with them too. If their answers do not satisfy you, you should cancel and move.
In business, the customer is right. Granted they can't ALWAYS be right, but they shouldn't be made to feel like an idiot either. Sometimes customers need to be corrected or shown when something is wrong, but HELPING a customer and TELLING a customer are two different things.
Just as you have an idea in your head about how you should be treated, your customers expect the same. Treat others as you want to be treated and everything will work out. You can not control the upstream, but you can remove your service with them.