IGNORE CANCELLATION REQUEST & FAILING TO CANCEL DEBIT ORDER

The end of 2020 I joined the Supersonic internet network. Very eager to get our business, but now that I cannot afford the monthly charges I cannot get them to cancel my subscription. The cancellation request was emailed to *** on 22/06/2022 and I received a phone call to discuss the request. I was informed that Supersonic will arrange for the router to be collected and I am liable for the R250.00 courier costs, this was agreed upon. The final debit order date was 08/07/2022. At the end of July 2022 I again received an invoice for August 2022. I cannot cancel the debit order on either the FNB internet or the FNB app. Now... what should I do... Supersonic won't stop submitting the debit order and FNB will not allow me to cancel the debit order.