MTN CONTRACT

I cancelled my contract on the 07 July which was due to end on the 30th July , they sent me a an email saying they will get back to me in regards with my cancellation , they didn’t then I went back to the store to cancel and I was advised it was not sent through,on the 27 July I got an email saying my contract was changed to month to month which is 260 -1160 but I didn’t want those services , on the 2nd of august they sent me an email saying my contact has changed to prepaid, then a few weeks later they told me I owe 1207 I asked for what they say for the month to month services, I contacted the call centre today and I was told that I must go abck to the store and ask the score to escalate it I mean?why? MTN is the pits especially with contract cancellations