Vodacom account

I had a cotract with vodacom that ended in july 2020,I am receving emails and calls from laywers who are saying I am still owing vodacom ,When i ask about the proof that shows I owe vodacom they said I need to contact vodacom they will tell,when I call them no one is assisting they are sending me back and fourth,I want to know what happen because the last statement from vodacom I was up to date