I was made aware of a purported debt many months after it had been sent to collection. I have never received a notice, call or letter from the collection agency ( Optima Recovery Services ) but they reported the debt to the credit bureaus and now my credit score has dropped significantly. 

I sent a certified letter to Optima Recovery Services in XXXX 2015. The letter explained I did not owe the debt and included a copy of the cleared check showing the item had been paid. 

I received no response from Optima and the item is still on my credit report.