Re: Can I fight this claim of ''breach of contract''?

Sorry to say you are 0-4. From what you have said there does not appear to be grounds for you to win a lawsuit. There could be some facts which you have not presented which could change our answers. Unless the note specifies otherwise, 10% simple interest is probably due on the note. The note probably also has an attorney's fees provision, which is the basis for seeking attorney's fees. All in all, your best bet is to try and settle with they guy.

I do provide debt negotiation services on a contingency basis. Feel free to contact me.

Re: Can I fight this claim of ''breach of contract''?

I would have to see the note before I could really offer an opinion about your chances here, but nothing you have said would support your position. Returning a signed promissory note by mail is just as binding as signing it in person, and there is no need for witnesses. Your own belief that you were signing in order to stop the employer's harassment and because you felt sorry for him is also not likely to matter; contracts mean what they say, even if one party secretly believes differently (in fact, that's pretty much why we have written contracts in the first place).

He can claim interest and attorney fees if the note so provides. Even if it does not, he can claim interest -- albeit at a relatively low, non-compounding rate.

Your statement that you received no goods, money or services in return seems to miss the point -- you likely got your old boss to refrain from suing you in exchange for the note, and that is a valuable thing. Now that you have stopped paying, he is no longer obligated to refrain from suing you.

You might want to show your note to a lawyer and see whether he or she can find something in it to support your position. From what little you've said so far, though, I can't offer any encouragement.

Re: Can I fight this claim of ''breach of contract''?

Apart from the facts underlying the reason for the promissory note, a signed note (with or without witnesses and with or without notarization) is valid.

Thus, to "have a case," you would need to show you signed the note under duress or that there was no legal basis for signing. Otherwise, you'll need to negotiate some kind of settlement with the holder of the note, or even consider bankruptcy.