Non-compete & severance

I had worked 10 yrs for a insurance broker. 7 yrs into the job the comapny was acquired - the new company required me to sign a non-compete and paid me $3000 to do so. 3 years later my job was eliminated and I was paid severance and some commissions due in exchange for my signing a post-employement non-compete that included a list of clients and former clients that I was not to solicit for 3 years.

One year later my new employer has obtained one of those former clients on the list - partially with my help. This particular client company had terminated it's relationship with my former employer 11 months prior to my termination. The contact at this client had also been a professional & personal contact of mine for more than the 10 years I worked at the prior company. (I knew her before I joined the company 10 years earlier).

(To make things more interesting, my boss at this new job is a former executive of the company that had been acquired who had left at the acquisition.)

I am now being threatened with a lawsuit to pay back the severance amount (10 weeks pay and commission) due to my involvement in getting this client. Because there are no damages (this client was not a client of the former employer for almost 12 months) my old company wants my severance pay to be paid back. It amounts to about $17,000 including commissions.

The policy manual does not indicate the exact severance policy but the practice of the company had been one week per year of service.

Does my prior employer have a case against me? Need I worry? I do not have the resources to pay the severance or the costs associated with a lawsuit.

The parent company is a publicly traded national company with about 2750 employees, 80 offices and is headquarterd in Virginia - although I always worked in the Syosset, NY office.

Any help would be appreciated!