Legal Question in Business Law in California

Re: over payment

You owe the money. You can either negotiate a repayment plan or they can sue you to get a judgment. If they get a judgment, they can put a lien on your house, garnish wages at your new job and other methods to collect.

Re: over payment

If an overpayment is made voluntarily with full knowledge of the facts, the payor has no right to recover the overpayment. However, if the overpayment is by mistake, which must be the case here, the payor has an equitable right to recover in most circumstances.

A person who has been accidentally overpaid is legally entitled to keep the overpayment only if two things are true: (1) the person has materially altered his position due to the overpayment, and (2) his accetpance and retention of the overpayment was innocent and reasonable. You seem to have "altered your position," i.e. you spent the money and can't get it back or easily replace it; but you would strike out on the innocent retention part because at the time you received the second payment you either knew or should have known that you weren't entitled to it.

There would also be a statute of limitations bar to recovery, but if the company is claiming it after only three or four months, this defense will not likely ever become available.