Revolving Loan

[sjs12]

Hi pls can someone clarify here for me. I have a revolving loan with Standard bank and the account is now up to date. Even when they charged the interest I squared up the account, now I have a debt collecter phoning me saying I haven't made a payment since June which is absolute garbage. I have now squared up the acc again after this lot and borrowed money end of July when (account was up to date) now they phoning saying it's in arrears when a debit order needs to go off end of August as per the agreement. Anyway I transferred money into it to clear it and now owe nothing on it. How do I stop these imbeciles from calling me day after day...