Anauthorized deductions from my bank account

I have a few months ago cancelled my cellphone contract. initially when i cancelled it the lady working and the vodashop in WESKUS Mall Vredenburg took all my details. sent me a cancellation email but never loaded it onto their system. So after the second time cancelling my contract i noticed that the debit order with the title "HOTSPOTTER" was continuously deducted from my bank account. i made sure that i told the services consultant that assisted me that i want all services on my name cancelled. i have since then on more than one occasion gone into the bank to stop the debit order and had to pay for that as well as paid for a reversal fee but each month this Hotspotter transactions reference number is changed allowing for this transaction to go through.