Product: Debt collection

On XX/XX/XXXX I cancelled my account with XXXX wireless. On XX/XX/XXXX I received an email from XXXX regarding my remaining balance {$1400.00} ( see attached # 3 ). 
On XX/XX/XXXX I communicated with XXXX via their online chat system ( see attached # 3 ) and asked if I would be allowed to return the phones, and was told I could return the phones to a XXXX store for credit to my account. On XX/XX/XXXX I returned 3 phones to the XXXX store and I called XXXX as directed to verify the return was credited ; I was told only 2 phones showed as returned in their system. I provided XXXX with the receipt number for verification and was told they would have to do an investigation into the credit for the 3rd phone. I was also informed that I would still be responsible for paying the {$1400.00} because I terminated my contract early. I informed them I would be able to make a partial payment of {$1000.00} as soon as I received the prepaid refund card from my new wireless provider, which could take up to 60 days to receive. I was told as long as monthly payments were made my account would remain in good standing and would not be sent to a collection agency. 
On XX/XX/XXXX I paid {$400.00} to XXXX via their online system ( which is shown in the bills sent by ERC ) and on  XX/XX/XXXX I paid XXXX {$1000.00} via telephone confirmation # XXXX ( also see attached # 3 ), and was told my remaining account balance of {$38.00} for the 3rd phone would remain in Sprints collection dept until refund was credited to account for the 3rd phone. I was assured the account would not be sent to a collection agency. In XX/XX/XXXX and XX/XX/XXXX I called to check the status of the investigation and was told I only owed for the wireless charging pad that I had financed for a total of {$57.00}. I paid the {$57.00} during that call for the charging pad and I was told that payment satisfied the remaining balance on my account. In total I paid {$1500.00}, which was {$19.00} more than the total amount I was told I originally owed. I did not receive any further bills/notices from XXXX after the payment I made on XX/XX/XXXX except for the {$1000.00} payment confirmation email I received on XX/XX/XXXX ( see attached # 2 ). 
In XX/XX/XXXX I received a collection notice from XXXX XXXX for {$600.00}. On XX/XX/XXXX I disputed the collection via CFPB and on XX/XX/XXXX XXXX XXXX deleted the collection account from my credit reports and stopped collection activity. However, on XX/XX/XXXX XXXX XXXX XXXXransferred the account to Enhanced Recovery Company , LLC ( ERC ). ERC began reporting this debt as a collection account in the amount of {$600.00} on my credit reports on XX/XX/XXXX. XXXX XXXX had no right to transfer/sell the debt to ERC because the debt is not valid, they were not able to validate or substantiate the debt, and they admitted such when they responded to my complaint against them. I am again disputing this debt, with ERC. ERC is also reporting two different addresses as theirs on my credit reports. 
On XX/XX/XXXX I submitted a compliant via CFPB regarding ERC 's attempts to collect the invalid debt from me. I had never received a notice/bill from ERC, and I also never received any phone calls regarding the invalid debt. I was notified via my credit monitoring service that ERC had reported the invalid debt on my credit reports in XX/XX/XXXX. After submitting my compliant to CFPB, ERC sent me several bills ( see attched # 1 ) and 2 lease agreements from XXXX. However, the documentation does not verify/validate the debt. It also does not reference the payment I made on XX/XX/XXXX in the amount of {$1000.00}. ERC submitted a response to my complaint with CFPB claiming their documentation validates the debt but it does not. 
The bills reflect accurate accounting until the bills marked " Bill Period : XXXX XXXX, XXXX '' and " Bill Period : Jul XX/XX/XXXX. '' The bill marked " Bill Period : XXXX XXXX, XXXX '' reflects a total amount owed {$2100.00} and states on pg. XXXX of 6 that the purchase option amounts of {$890.00} and {$590.00} XXXX {$1400.00} XXXX would be credited to my account once the devices were returned in good working condition. The devices had already been returned in excellent working condition in XX/XX/XXXX and the amount was deducted from the total amount owed on the final bill provided by ERC/XXXX. However, in the documentation provided by ERC/XXXX, an additional amount of {$600.00} was being claimed by XXXX on the bill marked " Bill Period : XXXX XXXX XXXX. ". This amount is inaccurate and does not reflect the amount shown on the previous bill or in the emailed bill I received on XX/XX/XXXX ( see attched # 3 ). The total amount owed, {$2100.00} minus the total amount due for the remaining monthly lease payments and purchase option price in the amount of {$1400.00} XXXX credited after the phones were returned ), should have resulted in a difference of {$620.00}. Once my payments of {$1000.00} on XX/XX/XXXX and {$32.00} on XX/XX/XXXX were applied I would have over paid XXXX by {$440.00}. 
ERC also claimed in their response that they mailed documentation to me on XX/XX/XXXX ; however, the only documentation they ever sent was on XX/XX/XXXX which was their response to my CFPB complaint. ERC also claims that on XX/XX/XXXX XXXX attempted to collect a payment of {$620.00} from me that was declined which is false. XXXX attempted to charge my bank account on XX/XX/XXXX in the amount of {$1600.00} and it was declined by my bank as a fraudulent charge ( see attched # XXXX XXXX. ERC claims XXXX wrote off the account on XX/XX/XXXX ; however, the final bill provided by ERC/XXXX shows they accepted a payment from me on XX/XX/XXXX and there is no mention of the account being written off/charged off. Finally, ERC claims the total amount due reflects all charges and fees through the port-out date of XX/XX/XXXX. This proves my payment amounts were after the cancellation date. ERC and XXXX did not provide any documentation that reflects my payment on XX/XX/XXXX. And the amounts shown on the final bill provided by ERC/Sprint show an inaccurate amount. 
My account was never delinquent with XXXX and they continued to accept payments from me after XX/XX/XXXX, which is the delinquency date being reported on my credit reports. I do not owe the {$600.00} or any other amount to XXXX or ERC because my debt to XXXX was paid in full in XX/XX/XXXX. In addition, I do not owe ERC for the invalid debt. Also, XXXX no longer owns the account as ERC claimed in their response because it was written off/charged off by them in XX/XX/XXXX according to ERC. ERC is attempting to collect an invalid debt from me.