MNT *****ulently debits from people's account

MTN doesn't tell customers that the home connects wifi is not fixed to R269,I was charged 489 on the second month.I canceled it and delivered the rooter at their Ghandi Square mtn shop but unfortunately the Shop Assistant failed to waver an amount of R2500 that is charged to the customer if they don't return the rooter,I got this R2500 information when I called the cancelation department.They now expect me to go back to the shop and ask them to waver that amount or charges will occur on my account which I didn't give them any right to debit from.

Mtn how are you able to debit from my account when I never received any debicheck from you? Do customers know that by paying online they are giving you access to *****ulently debit from their account?