Harrasment not finished

Standard Bank made a big big blunder on my account. After my account was closed I still received sms's and e-mails from them threatening legal action (collections). After many harassing messages I received a letter from Anthony, Richards and Associates in which the letter stated incorrect information ONCE AGAIN!! I responded and told the assistant to correct the letter. Since 14 July 2015 there has been no response form either STD Bank or Anthony, Richards and Associates. I cannot believe that our own company's/businesses don't care how clients are impacted by their negligence! Disgusting!!! I want this letter fixed ASAP or we will take the matter up further.