Need help defending my advertising agency's contract with client.

You've just described a common problem for attorneys. When an attorney sues a former client to try to recover unpaid fees, the client's response is often to claim the attorney committed malpractice. Now you know why attorneys routinely want retainers/deposits for their services!

It doesn't sound like a claim has been made against you yet, so like an attorney who is faced with the non-paying client, you have to make a business decision. Are the outstanding receivables worth the cost of defending a claim? One factor is whether your contract provides for attorney's fees to the prevailing party (and how confident you are in the contract). If the amount at stake is sufficient to make you decide to proceed with your claim, then any competent litigating attorney should be able to serve you well. Any specialization due to the nature of your business could be resolved by the hiring of an expert witness, who will almost certainly be necessary to your case anyway if it gets close to trial. Feel free to contact me for a free initial consultation.

Regardless of whether you go to litigation, it sounds like you should also consult with a transactional attorney regarding your contract. While you may have saved a little money to date by using a form contract or an existing contract, or making one yourself, those savings are wiped out by this instance - either by losing the receivables or by the cost of a lawsuit. Get an attorney to help draft a better contract.

DISCLAIMER: The information in and this communication are not intended to create an attorney-client relationship between you and me or my law firm. The information in this communication is intended for general informational purposes only and should be used only as a starting point for addressing your legal issues. It is not a substitute for an in-person or telephone consultation with an attorney licensed to practice in your jurisdiction about your specific legal issue, and you should not rely upon the information in this communication. You understand that this communication is not confidential and is not subject to attorney-client privilege.