Unauthorised debit

I took a cellphone contract to the amount of R299 in 2019 and it was for 24 months which ended on the 09th of December 2022 to my surprise MTN had debited my account at the end of November . I went and laid a complaint at one of their stores at the Standard Bank centre in the Pretoria cod area on the 12th of December 2022 . The consultant told me that I should have came and cancelled the contract and no one told me when I signed the contract in the first place. The consultant had then logged in a cancellation on my behalf with the reference number: ***.

I have tried to contact the MTN call centre with no help