Why do we stress, to cancel the contract with MTN?

Hidden costs when it comes to the cancelation of a contract. I canceled the contract as it was due for upgrade, I phoned the retentions department for the cancelation and it was canceled, I was also informed informed to pay R91,00 I don't know for what, because the contract has ened. After a month R105 was debited from my bank account of which I don't know what is it for? Furthermore I kept on receiving smses regarding the outstanding amount of R105,00 of which I don't know what is it for. Hello Peter kindly assist me with my query..... Here is one of the smes I received:Dear Customer,Your query *** has been opened. Please contact call center if you require more information. Thank you for using MTN. Have a Y'ello day. Furthermore why is this query opened because the contract was canceled at the right time. I didn't open any cellphone contract with MTN...And it is so stressful to cancel the cellphone contract with MTN.