Poor service and *********** staff

Poor customer service from.staff I've canceled a subscription in January with the lady at the call centre She sd it would be canceled and she will send me the form immediately for cancelation on the 3rd of January 2021 I received that cancelation form in February after me calling several times In the meantime I started getting emails and sms to say my account is in arrears by r 1800 And have to.pay it I spoke to the person that sent the sms he sd email all documents he will call me back and resolve the issue It's now 4 months later I'm still being billed and spoken to several consultants there calling in all the time no.one has ever returned my calls 13 April 2021 I spoke to the consultant he insists I.must pay this account I need assistance in this matter from upper management As his or hers staff are *********** of helping customers I will not pay that outstanding amount Now I receive a new statement saying I owe more I will not consider them for my new installation Please assist