1- Unless you stole $325.00 from them you owe them nothing.
2- Whatever you did steal I assume you gave back so, you owe them nothing.
3- If you have not been to work in 3 weeks you are already fired I would imagine.
4- If they threaten arrest in the demand letter you may have a claim against them.
Good luck in your next job.
If you have been threatened with a lawsuit, I would suggest you consult a consumer advocate in your area. And if you have been charged with a crime, or anticipate you may be, it is advisable to consult with an experienced criminal defense attorney in your area. You may find attorneys on this site, or by contacting your local bar association. He/she will be able to discuss the specific facts of your case with you and advise you of your legal rights and defenses.
Additionally, I also suggest individuals who have been charged with criminal wrongdoing refrain from discussing their legal issue with others absent instruction from their attorney. This includes posting information on the Internet, including this site. Doing so could compromise an optimal outcome and should be avoided.
Good luck to you.
NOTE: This Answer does not constitute legal advice. Every case is fact specific. To render a legal opinion, an attorney must engage in a consultation with a prospective client and review any pertinent documents. This communication does not create an attorney-client relationship with Attorney Amy L. Wells or WELLS LAW OFFICE, INC.