Vodacom Contracts, Customer Rip-Off

I recently discovered that vodacom listed me as bad payer for a cellphone contract that was paid and closed in November 2018. After several calls with their service consultants, one of them confirmed to me that it shows on the system that I have been handed over but it does not make sense because the contract is closed. My fone was moved from contract to pre-paid last year by (Ms Leshiba M) after they confirming that the contract was paid up. This is the same lady who tried so hard to convince me to get an upgrade and I refused. So is this the price I have to pay for refusing to upgrade?