Poor Service, over billing and *********** stuff

I switched from the R555 plan to the R650 plan, asked for a cancellation but because sales person was only interested in making a sales she did not cancel it, now i'm slapped with a bill for 1.2k and saying i should settle in order to cancel. I should pay for the bad hire rain does with *********** people who do not know the definition of Switch and Cancel. They need to do better or they will lose customers. Collections do not want to call and settle this, they do not want to listen to the recordings, no body is assist. I currently do not have network so il look for another provider for customers service is not important to them