Michigan Legally Banned?

I am an independent manufacturer's representative. I was recently contracted to represent a line of products into distribution within our industry. Upon his learning of my contract, the sales manager for the previous employer called the manufacturer and told them that he did not want me calling on them. This has caused not only an uncomfortable situation, it will cause me to lose income associated with sales to that company, since I cannot service the account, even though I call on end users within the distribution region covered by this company and am expected to represent the product line to those end users. Do I have a cause of action to sue the individual sales manager?

[AFFA]

I wish to inform you that if your previous employer does not want that you should call on them, it is the privilege of your previous employer not to do business with your manufacturer through you. However, when the manager made a call to your manufacturer and if he has defamed you during that conversation then you can file a case against your previous employer. You can also discuss with your manufacturer and give the account of your previous employer to another representative and pick up alternative account to compensate you for loss of business with your previous employer.

AFF