Blocking account without notification

On 4 September I attempted to move funds from my savings account into my Cheque Account which was owing an overdraft amount of R1600. However my account was blocked.<br> Later on I received an sms stating that my account had been handed over to attorneys.<br> <br> Surprised I then approached the Nicolway Standard bank branch and they confirmed the same.<br> <br> My issues are :<br> 1) How can I be sent to the lawyers after 1 month of using the overdraft facility. What is the purpose of the overdraft facility then?<br> 2) There was no notification from Standard in the form of a phone call or sms prior to blocking my account<br> 3) There was no call/communication from anyone requesting me to pay the required minimum payment <br> <br> Can someone please explain to me what happened on this case?