Vodacom is useless

I had a cell phone contract with Vodacom more than 20 years ago. It was paid up more than 20 years ago. Still they say I owe them money. I went to about 20 different Vodacom shops to ask for the statement, but according to each and every one of them I don't owe Vodacom anything. I communicated with Vodacom offices and send emails to Nomsa Mageba since November 2023 and on 3 January 2024 I asked for the contract to see who signed for it as it looked to me there is ***** going on here. She couldn't supply me with a contract. Now this amount is lying on my credit record as not been paid. I want my name cleared and Vodacom to supply me with the so called contract