Account payment gone missing and being threatened with legal steps

<p class="MsoNormal">Being a loyal customer and always paying my account long before the due date some month I even pay more or double, last month I paid my account on the 27^th same account details same reference no everything was the same, to my surprise I got a threatening sms from Telkom Mobile informing I will be handed over if payment has not been made, Yesterday I called them and send them proof of payment and again same result today another msg saying my account will be suspended and I will be handed over. I called again and again the are so unhelpful its shocking, they have already updated my credit report with no payment. I demanded an apology and I wanted to know why this happened and why they have not fixed it yet, this is a horrible network and their staff are completely *********** and are always full of excuses. </p>