Arrears on Vodacom Contract account

Good day My name is Lebogang Mariat Faith Petersen-Mahlaba ID:*** , I have a contract with vodacom , last year on the 22 September 2022 I request an early cancellation of the my contract they gave me the quotation of R2068.47 then the very same day I made payment of R2068.47 , which was agreed amount, now am getting calls from vodacom Attorneys saying that my account it in arrears, I fail to understand how is this possible am not happy at all pls help resolve this matter as a matter of urgency.