Did the company indicate that they are refusing to pay your severance because you filed for unemployment, etc.? I am trying to understand how the question is linked to the facts you then put in the body of your post. Next question -- how overdue are they? And have they paid others (assuming others were laid off/outsourced).
This answer does not constitute legal advice nor form an attorney client relationship. I am not your lawyer. If you have a legal issue in Maryland, Virginia, or the District of Columbia, you may contact me for a free consultation.
If your former employer entered into a severance agreement with you whereby they agreed to pay you a certain amount of money, and they are failing to live up to their end of the bargain, then your former employer can be sued for breach of contract. The amount of damages will most likely be governed by the terms of the contract. With that said, it is impossible to answer specific questions about whether you have done anything that could be used against you without reading the terms of the contract that you and a representative from your former employer signed. My advice would be to schedule a time with a local employment law attorney to review the contract and then answer any questions that you may have. He or she should also be able to outline what your options are going forward based upon this consultation.
Best of Luck!