Vodacom worst service ever received

I opened an account with vodacom in 2015 because of surcumstances my account was handed over to the legal department. I made an arrangement with them for a amount to pay off the just over R1000 that i owed. Money is being deducted from my account every month and should have been payed up a long time ago. Legal is useless when inquiring on my account the send me a debt collection agencies number that says im not even on their system. This matter is making my credit score listed as high risk and i can not even open an clothing account it is putting strain on my life and i request help from anyone who can assist as vodacom will not ever see me as a client again they are useless in every aspect of my encounter.