Inability to close matters out

I have been a Cell C customer for very long. Unfortunately my experience is that, over quite a while now, Cell C's customer support has steadily declined. A frustrating issue is that friendly call desk personnel interaction is not good customer service - customer service should be measure in terms of resolved challenges. My frustration has now reached a point where I want to get away from Cell C - I just cannot associate with the brand's false values. To this effect I paid the outstanding amounts (for the devices I have/due to the end of the contract) and final usage for Aug 17 as I was advised to do by a call desk person. The idea was that the sim cards would then change to prepaid sims. This need in order to port the numbers to a new service provider. As advised, I called back after 24 hrs to confirm - and was informed the system does not reflect payment. I had to call back after another 24 hrs as it could take 48 hrs to reflect payment. I done so and was told it still did not reflect and I had to call back in another 24 hrs. This I done only to be told payment still does not reflect. The suggested solution was then that I had to mail the proof of payment to ********** This I done and now need to wait again. Irrespective of the Cell C number I call - there is simply no closure. Mails I have sent from the Cell C website elicits no responses other than call back usually more than a week after the mail was sent. I get no written response from Cell C so that I have a record of proceedings. Only Cell C claim to record conversations - but I have no records. My frustration levels are high. I do not want this account to be drawn into Sep and be liable for another month's payment to a brand that I under no circumstances want to be associated with any longer.