In 2011 XXXX investigated this debt from XXXX XXXX and it was found to be not valid due to the inability of National Fuel to produce any bill that was in my name. Contract Callers Inc. is now calling on a daily basis stating it was my debt. I asked them for supporting documentation from National Fuel to verify the debt and they told me I could call them and verify the debt. I told them if they could not provide verifying documentation, they would need to cease and desist from any collection activities according my rights under the FDCPA. They refused to produce the supporting documents and said all they had to provide to me was a statement, written by them, stating that they were collecting a debt for National Fuel.They also told me that this debt was on my credit report. This debt is not on my credit report because it was removed once the XXXX XXXX XXXX XXXX XXXX found that it was an unverifiable debt. The harassment and strong arm tactics of trying to get me a pay a bill I am not, nor never have been responsible for is completely unfair and is infringing on my rights as a debtor.