MTN data contract **** by MTN

MTN refused to cancel contract, the contract came to an end & I also canceled it by phoning their call center & also visited their MTN store at Maponya Mall they gave me cancelation reference *** but to my surprise they keep on loading data & tell me to wait until month end it will be canceled, come month end they load data & say it's cancelation pending I just have to wait and pay for the data their loading, during the mid month they say is canceled and during time to load data it's open and data loaded & told I must pay