Contract cancellation

I am currently experiencing the most ********** experience with MTN South Africa. My contract came to end this month and I called them last week to ensure that I cancel my contract for no additional charges. I was taken back and forth between two departments namely being sales and retentions (a good one hour was spent on the phone), how I ended up in the retentions department was that one the consultants offered me an affordable deal which I was keen on taking on but due to the endless transfers between the two departments I ended sending their customer service an infuriating email stating that I want nothing to do with them cause my matter is not being attended to and my email trail still shows the back and forth I am currently experiencing between the consultants. No curtesy call has been made instead I got an email from a lady name Boitumelo stating that I had agreed to an upgrade, no care or attention to my matter at hand. I found it very rude and very unthoughtful towards the customer who has been suffering such grief from the network. I believe that she had seen and read my emails because she had the nerve to respond to the email with zero care or consideration to the customer. Furthermore MTN went as far as sending me a statement for the following month with a contract that has ended and an upgrade that is pending cancellation due to their horrific customer service.