[RR-NYC]

Sounds like a mistake of a disorganized company. HR should have taken care of the termination (voluntary or not) processes which includes payroll, health plans, etc. if you had health insurance and have not received a COBRA notice, you probably weren't removed from the system.

Your final paycheck should include any unused PTO been paid by paper check. In order to receive severance, you would have signed something regarding payment or you would have signed a separation agreement.

Like others have stated, I would contact HR immediately and be prepared to repay those funds or have it debited out of your account. Depending on the amount, they may pursue you legally if the funds were not able to be debited or repaid.