0 rating for Vodacom

dear Hello Peter

I would like to express my frustration regarding Vodacom. I had a contract that I decided to pay and close in 2017, My last installment was R428.80 which I paid by cash at Vodacom Gandi Square since I was working closer to the branch at that time. This year January 2023 , I am reviewing my credit record , which I do every year and boom*** I see myself with an over due amount of R3157 from vodacom. luckily , I still have the statement indicated my balance in October 2017. unfortunately I used cash to balance the money owed at the time and do not have any proof of payment anymore. Can someone at vodacom please tell me what is going on and if I really were owing them and not finished why was the record not on my credit for all these years till 2023.