No right as consumer / customer

Very Bad service I bought a laptop with an office program included in the package, on contract from Vodacom. I collected the laptop on 9th September 2016 and took it back on the 12th September 2016. I told the manager in the Vodacom shop that we could not load the program onto the laptop and I want to cancel the contract. He said that they cannot cancel the contract but they will fix the problem with the laptop. I said that I don't want something that need to be fixed even before I could start to use it. After I could not get through to any one in the shop I left the laptop there and left the shop, very unhappy. Days later I got an email from Vodacom customer service to find out if I am happy with contract and to welcome me as a customer. I relayed to them that I gave back the laptop and want to cancel the contract as I don't want something that gives me problems even before I start to use it. - NOTHING was heard from customer service again. Then I sent customer service a mail to cancel the contract and got a Ref no:003S-SCR4 After many mails and no response other than the same ref number I phoned them 27.09.2016 @ 13:16 the call ended 13:30. The guy that eventually was willing to listen to my story told me that I have a good rating with Vodacom (4 contracts) he could not understand why they would not cancel this laptop contract. He gave me a Ref no: S3-G6627-739F1 for the call and said that Vodacom should contact me in a day or two. Two weeks later and no call from Vodacom or customer service. I received an invoice from Vodacom for the contract 07.10.2016 This meant that they just ignored my cancellation request and - me as consumer had no rights. I went back to the Vodacom shop and they told me that they could not get the laptop to work - now with them for + - 6 weeks. They then still refused to cancel the contract and I took the laptop (now blocked) from them. On 17.06.2017 I went to the same shop and asked them to give me the total amount outstanding on this account and I paid the full amount R11 776.32. I instructed them to close the account and I did not want anything to do with Vodacom again. They told me that it is ok and I left under the impression that the account / contract is now closed, done and dusted. To my great surprise I got a call from Vodacom telling me that they handed my account over because I am not paying my account this was in November 2019 - 3 years after I paid the account in full and told them to cancel this contract.

What is my right as consumer? How do I get rid of Vodacom?

Very Upset and Unhappy customer