MTN are bladdy *****s

I have cancelled my data contract on the 1/12/2021 which I had for more than 2 years with mtn and was told that my last payment will be on the 1/1/2022 by Notando Mdayeni which I agreed too. Thereafter I have received numerous sms's that my contract has opened and closed then opened with new dates and instalment amounts which I am not aware of as I said I have cancelled and got a reference number as well.Today I called and was told by Slindokuhle Ndisane that I will be billed at the end of January like what the hell is going on with mtn?I have always been a loyal customer and this is the service I get just because I cancelled!I need someone with knowledge to call me and explain what the hell is going on as this is not acceptable....