Bad Service Ackermans / Tenacity

After falling behind with my account by one month, the following month i had done an electronic transfer into the bank account of Ackermans with my given ref number.The transfer has been done on 24 August 2019, and proof of payment sent through to Tenacity which confirmed they have received the relevant pop. I was then told it would take five working days to update, to date i am in undated with calls and demands for payment of three months. Yes i am aware that the account lagged behind by one month, yet was rectified the following immediately. I just feel that the badgering, and demands for payment is just not the correct steps taken in this instance as payment has been received in full and up to date. Yet this actions or negligence could have a negative affect on the consumers credit profile.