You do not have to take the company's word for the fact that it was overpaying you and should demand an accounting showing the overpayment. The company could sue you and assert contractual and/or unjust enrichment claims. However (depending on the amount in question) many employers would not go to the extent of suing an employee and having to admit its own stupidity in not knowing how to calculate pay.
Answered on Apr 10th, 2013 at 7:09 PM