Telkom's mediocre online presence

I have been a Telkom client since 2010 until October 2018. I recently moved to another area and wanted to discontinue the line. Because I have been with them so long I was not bound to a contract and that I can pay month to month. I have been to the store to cancel but was informed that all cancellations takes place online. I was also informed that one cannot call to cancel you have to do it online. I immediately went online to cancel but there online presence was so poorly set up and not client friendly at all. Their online system made no provision for contact numbers to call if you are struggling with your online application. I tried several times to cancel, but the system continuously rejected me on my landline number and informed that I was non existent. I have been overseas since November and I have not contacted them because I was under the impression that I cancelled and because I was non existent it was resolved. But I have just recently been informed that I owe a balance of R5100. This obviously affects my credit rating and one cannot apply for any financial assistance from any bank. I am now deemed as a bad payer. I am trying to resolve this matter online again and have made several calls to explain my situation. I have just spoken to a consultant and explained my predicament, I am still liable for that money which I refuse to pay. The consultant informed that they know that their online presence was poor in the past but it has been updated two months ago. My question is then if are bound to a contract I can completely understand why you will receive a outstanding bill , but if you are not bound to a contract and you can pay month to month what are the implications then? In my opinion I made all the effect to go in store and cancelled online which is just the right process to follow wether you are on contract or not. Why should I pay an outstanding bill because of Telkom's mediocrity and how can I be liable for not utilising the product? I can certainly accept that I am liable for the outstanding costs of the Telkom landline only. Additionally the consultant informs that I cannot cancel before settling the outstanding debt. I have disputed the matter today and I will only hear the outcome in 7 to 14 working days. This means that until then depending on the outcome they will bill me additionally for the month of June with added interest. This is absurd. I am also trying to locate their customer service email address, there is only is number to call free from your Telkom line. Understandably calling from a cell phone becomes expensive and in my view it is always best to have evidence in writing. I have now almost exorsted all options with exception of the onbudsman, I need assistance to resolve this matter.