TELKOM OVER CHARGES ME

I took a contract with telkom in 2017, of which from the word go i was given a wrong deal they got back to me 4 months later to correct the deal which they were charging me over R400 monthly whereas i app**** for a deal for R100, to cut the story short i continued with them up until 2019 November, i app**** for cancellation and i filled forms, only to realize even in 2020 they are still deducting and i have been calling them and going to the store they always say i must call telkom but i get billed every month even after i have CANCELLED.