Product: Debt collection

I XXXX XXXX XXXX paid {$260.00} on XX/XX/XXXX to the collection agency after speaking with XXXX at XXXX and was told after intercept of XXXX income taxes in the amount of {$2300.00} that my account will be paid in full once I paid the remaining balance of {$260.00} and a letter will be sent to my hone ( see letter dated XXXX XXXX ) I received a check in the mail in the amount of {$2300.00} ( same amount of my income tax interception ) due to the XX/XX/XXXX th the presidential mandate cares act that was passed by congress the emergency legislation intended to meet urgent public health and economic needs in the face of the coronavirus crisis. 
I have since then received information from the credit bureau that my credit once again has been effected and my scores have dropped and received phone calls from XXXX ext. XXXX and was informed I have a balance and that I now owe a total of {$2700.00} due to an additional collection fee of {$420.00}. After several attempts to contact someone. On XXXX I called and was transferred to XXXX XXXX XXXX ext : XXXX and stated I wanted to pay the amount that was sent back to me and did not agree with the additional collection fee. I asked her to repeat the collection fee and she stated she could not provide that information, but I was able to provide her with the information due to previous conversation with another agent the week of XX/XX/XXXX. The bottom line is if the amount of {$420.00} that has not been disclosed in any form other than in conversation is believed by me to be additional fees because on XX/XX/XXXX I called to inquire of the balance so I could pay it in full and was told there was only {$260.00} remaining on my account and if in fact there was this collection fee from the time I was in collections the true balance would have been {$1000.00} if in fact this is the true collection fee since XXXX said she could not disclose that information and I have not been provided anything in writing. 
XXXX the provided an address at my request so I can send a written concern and she began to question if I was refusing to make a payment. 
Since the refund check from the agency has been sent back I have never received a written statement or letter with explanation provided to me of balance and collection fees. Im not trying to argue the fact that there is now a balance due to the returned check, but I am not agreeing to pay a fee for recollecting a PAID in full balance due to the presidential mandate. I paid all interest and collection fees associated with this account once and I should not be liable for this collection fee and furthermore my credit should not have been damaged due to the return in fees. 
XXXX the provided an address at my request so I can send a written concern and she began to question if I was refusing to make a payment. 
Since the refund check from the agency has been sent back I have never received a written statement or letter with explanation provided to me of balance and collection fees. Im not trying to argue the fact that there is now a balance due to the returned check, but I am not agreeing to pay a fee for recollecting a PAID in full balance due to the presidential mandate. I paid all interest and collection fees associated with this account once and I should not be liable for this collection fee and furthermore my credit should not have been damaged due to the return in fees.