Position Misrepresented

[expo421]

My question involves labor and employment law for the state of: Michigan
I was employed for many years by Company A. I was eligible for retirement, but wished to work for a few more years to improve my financial situation.
I was approached by an executive from Company B. He offered me a position, and provided a written description of a newly created position in his area. He knew me professionally from previous business activity, and was certain I was perfect for this job. I concurred, and said I would accept the position under the following conditions:
A specified salary and benefit package.
I would retire from Company A at a reduced pension, and 'make-up' the difference working for him for a few years.
I would need 3 months or more to initiate and complete the retirement process with Company A. Following this, I would immediately start work with Company B.
He agreed with this, and I initiated and completed my retirement from Company A.
When I started work for Company B, I was asked if I wouldn't mind temporarily working at one of their other sites in a different role for a few months, as this site was having difficulty in areas which I was very qualified. Also, I signed a letter prepared by the HR director which outlined my compensation and job classification. The job classification was general in nature, not the specific title previously described to me.
I completed the temporary assignment, and began performing the job I was hired for. However, I was repeatedly asked to take other 'temporary' assignments in areas outside the scope of the job described in the hiring offer, and 'temporarily' report to directors other than the person who hired me. Recently, I was advised that the company needed my to continue doing these other assignments, and my pay would be cut to a level more typical to these reponsibilities. It is clear to me now, that the 'newly created job' was actually a fantasy, and was so the day I reported to work (This position still does not exist).
I never would have retired from Company A if I was offered the job I'm doing now. I feel I was misled, that Company B should have withdrawn the job offer, or advised me of their other plans for me before I separated from Company A at a finacial disadvantage. Do I have cause for recourse?

[Mr. Knowitall]

What, if anything, do you have in writing? Just the initial offer of the job, title and wage? Anything that commits to offering that job for a specific minimum period of time? Was any promise as to the duration of this position made, in any form?

It's permissible for an employer to change your job title, job duties, job description, and even your wages after you're hired, as long as it's consistent with your contract.

[expo421]

I was given a written description of the job in my interview. This, together with the agreed upon compensation package was the basis for my acceptance of their offer.
On my first day of work, I was provided written commitmentment to a 6 month review of my performance, as well as annual review to be conducted thereafter. None of which ever happened.
After 7 months, I submitted a written review of my progress on the 'temporary assignment' given me on my first day of work, as well as recommendations and a plan to transition to job I was hired for. I received no feed back, just more 'temporary assignments'.
I feel that some time between my acceptance of their solicitation and my actual hire date, the company decided that they needed me more for these other tasks than the job which was offered to me. There is no doubt in my mind, if I had known this, I would not have left my previous emplorer (at financial disadvantage) to assume these 'tempory assignments'. I feel they should have advised me of the change in responsibility before I reported to work, and given me an opportunity to re-assess their offer.