Product: Debt collection

I filed a previous claim with CFPB ( Case # : XXXX and XXXX ) on XX/XX/2016. I have received another letter from a different debt collector regarding the same issue. The debt collector is ERC. The initial claim stated : I agreed to a one year bundle package with XXXX XXXX with a specific guarantee of quality of service. Specifically, I required a specific upload/download speed for my broadband connection in order to connect to a government XXXX connection in order to telework. At no time did I speak with a XXXX person until the technician arrived to install the equipment. The broadband connection routinely fell below the required speed to keep the XXXX connection which jeopardized my ability to telework. XXXX attempted to correct the issue, but all efforts failed. Consequently, I changed the provider of my bundled services. I contacted XXXX and advised them I was cancelling my service due to the above issues. I was informed I would pay an early cancellation penalty since I did not keep the service for the two year period. I informed the Customer Service representative I did not commit to a two year agreement and this was the first I was hearing from them. I did not receive any correspondence from XXXX at the time I agreed to the service with the XXXX representative. I received monthly bills from XXXX. I contacted XXXX several times after I cancelled my service to get an explanation to the charges. I returned the equipment in the prepaid postage container, but was not credited for the equipment. The remainder of the balance was said to be " unpaid charges to XXXX ''. I asked twice for an explanation and received the same explanation. I was then contacted by a debt collector, XXXX XXXX XXXX , XXXX . I explained the situation to them ; however, they persisted with repeated telephone calls and correspondence. I responded to The XXXX XXXX with a letter providing the details and copies of billing statements from XXXX and XXXX. The XXXX billing statement showed no balance due. I received a response from XXXX XXXX along with a letter from XXXX. The letter from XXXX stated the XXXX and XXXX statements were integrated and XXXX and XXXX removed the integrated billing option ( which occurred shortly after XXXX XXXX XXXX acquired XXXX ). The letter when on to state, " The account balance includes XXXX charges which were unpaid by XXXX. '' I sent a subsequent letter to XXXX XXXX stating the collection of unpaid charges in between XXXX and XXXX. I requested XXXX XXXX stop all communication with me and with my address, and record that I dispute having any obligation for this debt. I informed XXXX XXXX that if they stop collection of the debt, and forward or return it to another company, to please indicate to them that the debt is disputed. Additionally, I asked if the debt is reported to a credit bureau, or already has been reported, also report that the debt is disputed. I did n't hear back from XXXX XXXX. About six weeks ago I received a telephone call from XXXX XXXX XXXX. I returned the call and asked what this was in reference to. The agent stated she need personal information from me before I she could tell me what this was about. I refused to provide them with personal information and asked them to forward written correspondence. I continue to receive daily phone calls with voice mail messages. One of which was very personal in nature ( I have a copy of voice mail ). This past week I received written correspondence from XXXX XXXX indicating the debt was with XXXX. In addition to phone calls to my residence, I now receive phone calls to my cell phone. When you answer the call, no one is there, the phone clicks, and you hear dial tone.