Falsey blacklisting my name

I took out my first contract with vodacom in 2012/13, i took an early upgrade in April 2015, and i had great service and was paying well through debit order till July 2016 when i called to find out how far my contract was to ending as i wanted to pay it off and end it. i spoke to a consultant by the name of Mariana and she let me know that i should make a last pyment of 267.00( i cant recall the actual amount) and my contract would be done and paid. i asked her if this would be the last payment and my contract/account would be finished. she assured me of this.

A year later, late 2017 i recieve a call from debt collectors for vodacom saying i owe Vodacom 4500+-. - i need to know why was it only picked up a year later that i owe vodacom? - why did debit orders stop if i was already paying through debit order? - i have been requesting the recording of my last call with the consultant and no one can provide it. - why did vodacom not call me a month or two after payment was "supposedly to continue"?

Trying to find out why the amount is so high, they advise i was still using my number, i never used the vodacom sism card from day one of recieving it. - i need to know why i am been given the run around?

i have failed to get any of these answers through the customer care or the debt collectors. my name has been blacklist and all i want is for it to be cleared, i am even ready to involve the ombudsmand as noone from Vodacom is willing to help me.