account update dispute

i had lodged a complain that was logged via hellopeter on the 15 January 2019, regarding my account . I received a call from your organisation updating me that my query has been resolved on the 16 January 2019. To my surprise today the 13 March 2019 was told that my account was has been handed over. I have already paid the account via DMC debt collection and obtained a paid up letter . My account was settled in December 2018. Please advise me what should i do , because its your incompetence . Spoke to someone today on the 13 March 2019 advise me to send the paid up letter to them. My id no ********** 964083