Disability Overpayment

I had knee surgery in September of 2000. I filled out the necessary p/w provided by my HR Rep. The time first requested off of work was for one week. After returning to the doctor after surgery, it was necessary to be off of work further. I faxed all of my necessary paperwork, doctors notes, not returned to work notes, to my Administrative Manager. I heard nothing from my HR rep, so I continued to fax in my doctors notes as I received them. I returned to work after being off a month. I got a phone call from someone at the benefits office stating that they are reviewing my Long Term Disability Claim. I called the person back and advised them, that nobody from the HR department told me that I had to submit a long term disability application. They then told me that my file would be in review and I would hear something pending their investigation. Well I have moved on to a different company and have rec'd a letter in the mail from the legal department advising me that I have been overpaid for one weeks worth of salary, and that I must pay them back or they will forward my file to a collections department.. Can they do that when it was their mistake in the first place?
Please advise. Thank you

I am a law school graduate. What I offer is mere information, not to be construed as forming an attorney client relationship.

I don't think so: they cannot take it back from you when they gave it to you -- called unilateral mistake. You had no knowledge of their mistake.

Let them know if they attempt collection, you will countersue fraudulent civil action. Suggest they take it as a tax deduction! :- )