Mtn is robbing me with a contract. 😡😡😡😡

Last year I signed a Black Friday Data contract for 200gb 18months for R299. In signing the Black Friday contract i cancelled the month to month contract for R432 200gb that i had. To my surprise this year i am still on that month to month contract. I am being taken from pillar to post at the store, on Twitter DM and also 135. I am fed up!