Viacom is debiting me without any authorization

recently I have been getting debit orders from Vodacom which are not authorized! Vodacom has taken over R2000 rand from me over the past 3 months and I have been trying to stop this to no avail.

I want my money back that Vodacom has debited off my account I have sent an affidavit to their ***** department already and now I'm sending my second. I want this issue sorted as I have not had any contracts with Vodacom for over 7 years and did not renew anything with them.