Ack, I'm sorry you had such a bad experience! You know... it depends very much who you speak to, most are extremely nice... but you might have gotten the one grumpy Rep.
You can complain to Koodo if you know their name and also I suggest you call again. Let's see if you get a better experience next time!
You never said what was incorrect on your billing. Care to share so we know what you are talking about? Often people think their bill is incorrect, turns out most of the time people misread their bill and actually there is nothing wrong with it.