Yup, it happens all the time.   Currently, 6 months into a job where I'm on my 3rd boss and second employment contract & associated pay plan.  Totally not what I signed up for in October.

And the promised territory has been changed for a lesser one with my commissions significantly reflecting that move.  

But I guess all is okay as today I got yet another accolade from the VP about how great I am doing, along with a request to sit down and discuss the secrets to my great work so it can be used to help others.

Not the first, nor likely, the last employer to misrepresent what's to be expected.