Netstar can't count

I indicated at least 2 months prior to the contract ending that I would not be continuing with the contract, however the debit order remained coming off my account. I instructed my bank to cancel the debit order and I then started getting emails and even calls from debt collectors that I owed money. I paid for the 36 months as per the contract and now they want me to pay more. I even spoke to the debt collector lady and informed her that I followed due process and then she said she would call me back after she verified what I said to her...I am still waiting for that call although Netstar has sent me again today (12 Sept 2018) a threat about legal action for just over R282.77 There are a number of other complaints about Netstar from other consumers, so why is nothing being done about this or does the consumer protection act need to be consulted as well as the Ombudsman for Banking Services (OBS) ? Bullying of individuals by large organisations shows a lack of ethical practice and indicates underhanded tactics to scare people into paying for something that they are not always necessarily required to pay...shame on you Netstar!