Following are the essential steps involved in writing a proper termination letter: Start with the date. Address the employee. Make a formal statement of termination. Specify the date of termination. Include the reasons for termination. Explain the settlement details. Request them to return the company property.
Just make sure you document the termination process well, including evidence of the misconduct. Write a letter of termination listing the behavior and reason for firing, and save a copy for your records. This will serve as valuable evidence if you need to prove it later on.
If you're fired for cause, which it sounds like you will be, then they don't need to give you severance. Normally companies will give something to avoid getting sued for wrongful dismissal, because normally there are steps they need to take in order to avoid those kinds of lawsuits.
Severance is never a requirement of any employer unless you have a signed employment agreement stating otherwise, or, it is a written policy of the company.