Making fun of clients and not attending to migrate

I have been attempting to cancel my contract and migrate to prepaid since July 2017. It is almost impossible to get through to the cancellations department, so last week I went to an MTN store on 12 Sept, who connected me to, whom I thought was a retention's agent, as this is what I was informed. He assured me that the migration to prepaid will be done within 24 hours. My reference was ********** 96. A week later and still this was not done. I phoned again 16 Sept and was informed that the migration was not requested and they cannot assist me as the cancellations dept is only available on weekdays. Today at exactly 08:01 I phoned and at last was put through to the cancellations dept, I spoke to a lady and she advised that the guy I spoke to was not from retention's and he only sent through an e-mail and they have a backlog so they did not attend yet. She then tried to sell me an upgrade!!! After a while at last she confirmed that she has now migrated me onto prepaid. She then thought the line was dropped and I overheard her make fun of me to her colleagues and have a laugh because I am unhappy with MTN....Great work MTN, this is why I am leaving you after 15 years. Your customer service is really horrible and you don't make any effort to improve. Happy to leave you!