The business plan of most debt collectors is that they will sue you for any debt and hope that you don't answer so they can get a default followed by a default judgement against you. So, whether you owe the debt is irrelevant at that point. Take care. The first that you do when you're being sued is answer the complaint. Find out if your truly owe the debt. If you don't do anything, something will be done that you may regret later on down the road.