Whenever you speak with someone at a company, the IRS or any governmental organization, get it in writing. Their failure to object to its contents may be deemed an admission of what the letter states. Keep a copy in your file in case to have to prove the oral conversation in court. The written word is your most powerful weapon in Court - use it. Do not write offensive letters to your adversary stating your legal positions.
Successful litigation involves some element of surprise.
State firmly, but vaguely, that you intend to pursue your legal remedies . . . Don't place all of your eggs in one basket. While a corporation or limited liability company may shield your personal assets from business liabilities, it will not shield the business's own assets. If your business entity has a substantial amount of debt-free equipment or real estate, consider spreading out the risk. Create one or more corporations or limited partnerships to hold title to the assets, then have your business lease the assets back.