Product: Debt collection

Approximately around XX/XX/2019 I started receiving phone calls from a company called Credence. A young lady greeted me and she said Credence is a debt collection company regarding XXXX XXXX XXXX XXXX and said I owed {$510.00}. I asked for what and she asked if I had cell phones and I said yes. She read all four ( 4 ) of my cell phone number 's I have with XXXX XXXX XXXX and said it's for the cell phones I have ( she also had my home address ). I told her I still have my cell phones and I have been paying XXXX XXXX XXXX monthly for them in cell phone charges, taxes etc. The young lady I was speaking to said she would transfer me to her supervisor and I explained the same thing to him. He then said ok, this is what we can do ... we will lower the balance you owe of {$510.00}. I told him that I would like to speak to XXXX XXXX XXXX and I also asked him to mail me something in writing. He said ok let me get them online and we'll do a 3 way call. He did call XXXX XXXX XXXX and it was a recording saying they will be right with us momentarily. However, we were on hold for a while so he said that they would call me back tomorrow. And I said ok. In the meantime, I called XXXX XXXX XXXX myself, I was able to get through, I spoke to a customer service representative and explained that a company was trying to say I owe {$510.00} for XXXX XXXX XXXX XXXX , XXXX XXXX XXXX checked my account and said I have a {$0.00} balance. They said that the next time I speak to Credence I can advise them to call XXXX XXXX XXXX and I agreed. The next few days Credence called my cell phone numerous times, I would answer and I didn't hear anyone on the other end, once I said hello they would hang up. This went on for a while, sometimes I would just ignore the call and would not answer. Today, XX/XX/2019 I received a call from them again, I answered and no one was on the other end. This time I called them right back and right away a man answered. He had my name, cell number and even verified my home address, I confirmed. He told me about the amount I owed and I told him that I've spoke to them a couple weeks ago and that I have even spoke to XXXX XXXX XXXX and that I do not owe {$510.00}. I explained to the man that usually when your account goes to collection that a bill would come first from the company which would be XXXX XXXX XXXX trying to collect the amount, then if I didn't pay they would send to collections. I told the man that I have not received a bill from XXXX XXXX XXXX ever for {$510.00}. And furthermore, I had contacted XXXX XXXX XXXX and they said I have a {$0.00} balance. The man continued to say that I owe XXXX XXXX XXXX XXXX. I told him that I did not have a {$510.00} balance with XXXX XXXX XXXX, I also said they should call XXXX XXXX XXXX themselves to verify I have a {$0.00} balance, I then went on to say that I still have my phones, that I pay monthly for cell phone charges and I thought that they are a fraud company and I wanted them to please remove my cell phone number from their list, because I get a call everyday from their company. The man said ok I'll remove your number from our list then and he hung up. That was the end of our conversation.