Legal *******

So I received an SMS out of the blue saying that I owe JD Group R6979.80 with a threat that I should call Landau Attorneys to avoid further action. Ref LA074817.... to my knowledge my account has been settled years back. In fact I cannot even remember what the account was for and I have never been contact by the JD Group or any law firm prior to receiving this sms. Like really what the hell, My accounts was settled more that 3-5 years ago as per the original agreement by debit order. and once the amount was settled THEY STOPPED DEBITTING debitting my account. Like what the hell, if they had an issue then why was this not brought to my attention years ago. As far as I am concerned, I was not aware of any outstanding debt.