MTN contract cancelation nightmare by MTN Branch

I went to apply for a contract. I was told to wait by Cape Gate staff member "Lisa" that I will receive a message that the contract for data was approved. That didn't happen. The only message I received was to say "pre-approved". So the first thing that bothered me was the fact no one came back to me(and the fact that it didn't happen as promised within 24hrs) to say that I must come and collect my data sim. Nevertheless, I went there yesterday to cape Gate branch, and when I arrived the consultant asks me with a luxidaisy vibe,"Oh I see you came in, and why didn't you come the same day?" I was a bit aggrevated by the comment and behaviour of the consultant, then again, I went through with the contract request,after having to go buy my own sim at PEP stores, since this was the only place in cape Gate that had a simcard available,closest to the store(not even the other mtn branch). Yet I went and signed a contract after specifically asking about coverage at my address. That was confirmed to be 100%, and I told them that I need data asap,since I need it urgently for alot I had to do. Today when the sim card became active,the connection seemed to be poor using an lte router,and it was a buffing and loading the whole time,it just got me so frustrated. I just can't deal with this right now. I need to use app's today and not tomorrow. I went to the branch where I took out the contract to cancel the deal,since connection is important for me,since time is money in my world. Now the branch manager comes and tell me,we will see if this is going to be cancelled. I am sorry,but I refuse to pay for something that is not sticking to the agreement to providing a service to my saticefaction. (Breach of contract-which makes this contract void). Please cancel this contract with immediate effect. It wasn't even necessary to test the service for 24hrs. The little I tried to log into sites proved to me,that this is not going to be the service grade I need to keep me at the edge of my research and more. My mtn number to be cancelled is ***. My contact number ***.