Yeah my uncle had a similar thing happen to him except he wasn't smart. Eventually the company in question worked out that the amount of money they thought they should have, was not the same as the amount they actually had, and did an audit, and worked out what had happened. But by this point my uncle had spent the money, because he's an idiot.

Keeping it in a high interest savings account is a good way of having your cake and eating it, even in the case that they end up chasing for the money.