I accepted a job offer and gave notice to current employer. Now new employer is telling me I am not a team player if I'm not willing to work 60 hrs. a week for much less money than first offered. I signed on for 40 hrs. a week at a set hrly. pay. This is not what we discussed or negotiated prior to my giving notice at current job. What do I say to new boss to get back to what was originally offered & understood? My current employer has already hired someone to fill my spot.
Executive Summary: There's a fair chance you're screwed, and will be working long hours for low pay, while conducting another job search under unpleasant conditions.
First, learn the lesson. You do not EVER formally accept a job offer, and take other irrevocable actions, until and unless you have the formal WRITTEN offer, on their letterhead, in your hands. You now know why.
How long can you afford to be unemployed, no money coming in? How healthy is your local job market?
If you can afford to walk away from this job, and search for another one, DO SO. Their action was highly improper and grossly unethical. You don't want to find out what they will do down the road.
How good is your relationship with your current employer? Even though they have hired your intended replacement, they may well be very happy to keep you aboard, and use the new guy to pick up slack that wasn't already covered. This kind of thing DOES happen, for various reasons. You will save them a lot of training costs and lost productivity if you stay with them, and (presumably) you've been a good employee and a valuable resource to them.
You say you started part-time. Are the rest of the full-time people working 60 hours a week? What do they think about all this? How many of them are looking for other jobs? How many have already left?
If the boss who pulled the switcheroo (American colloquialism) is someone new, you can talk to the guy with whom you negotiated the original offer, and see if he can intercede with the Big Bosses higher up the food chain to reinstate the original offer.
If he is the same guy you've been working for all along, the guy you were negotiating with, you've got a serious problem. You now know that he is not the slightest bit troubled by any trace of professional ethics. Things can only get worse, and they WILL only get worse. You can try saying "Excuse me, but we agreed on X money for 40 hours, not Y < X money for 60 hours. What's going on here?" and then SHUT UP. How he answers will give you some insight.
Do you have friends at other firms locally that are looking for help?
In the worst-case scenario, your current employer won't take you back, you can't afford to be unemployed, all attempts to get the original offer reinstated fall flat, and you are in general screwed. In that scenario, you will be working long hours, for low pay, for the absolute minimum amount of time it takes you to find another job.
It might help you to talk with an attorney who specializes in labor issues. He can tell you what kind of documentation you should be keeping through the process, so that when and if they pull the next surprise party, you'll be prepared. His first comment will be along the lines of "This is why you get it in writing."
Soldier on until you can find a new job. Bosses like this are NOT good for your future prospects. I have seen many bosses like this, they tend to have high turnover and don't care about their staff. They just want to get more than their moneys worth out of you and they'll work you until you drop if given the chance.
In some industries this makes sense from a business point of view.