Frustrated with MTN not communicating to me on Cancelling my contract

I have upgraded my data contract on the 27 September 2019 with a Laptop Deal. It was a Lenovo laptop which has an Intel Core i5 processor. Since I am using a Acer Intel i3 which is probably a student range, I thought the Lenovo Intel Core i5 would be faster. Anyway after fetching the laptop and installing the FREE office that was part of the package, I had nothing my endless handing on the Lenovo laptop. I reported the issue to the store and then made contact with First Technologies who assist MTN on the repairs. After testing etc, a Credit was granted to me. I was not asked if I which to cancel or take another laptop but the same Lenovo laptop was ordered for me. I then asked the gentleman at First Technologies, if this laptop does the exact same what happens then. He said I must send it in and they will sort out for me. That exactly what happened. I received the 2nd Lenovo laptop and the same night I installed the Free Office and tested to see if the laptop was stalling or slow and it was even worse. The laptop was handed into the First Technologies immediately the next day for testing and after more than two weeks they come back to me to say that there was nothing wrong with the laptop. I asked them if they installed Office and tested for the lagging and they confirmed they only tested the hardware. Since taking signing up this contract in September 2019, its now 11 December 2019. I have not been given any constructive feedback from the store, I had requested that this contract is cancelled and I would take out a new contract with a different laptop but still I have not heard from anyone, I have emailed continuously and called the store more the 3 to more times in a day and I have not received any responses. I am now frustrated with no answers and paying for a contract I am not using. The Laptop is still in the care of First Technologies. This laptop has been passed from hand to hand and god only knows the condition of it and to me this is NOT a brand new laptop. I refuse to have something that wasnt in my care for than a day and refuse to pay for a contract for 36months on a laptop was sent around many people. I urging MTN to response or I am seeking legal representation. Just to add that both the Lenovo laptops was handed in within the grace period which a customer is allowed.