From a legal point of view I don't think you have a case.
You've only been there three weeks for a start, so haven't given it enough time.
Plus if one or two people do earn the level you need to then, strictly speaking, they haven't lied in saying it's possible.
With commission based work the onus is on you to achieve targets. They'll simply argue that it's possible.
BUT if it's dull work then I think you should pursue something you will enjoy much more.