Bad Customer Service

I have been trying to cancel my vodacom contract since June 2026. No help from vodacom. Please note. On 26 June 2026 I sent mail confirmation of cancellation of contract. Received acknowledgement same day automatically. Re-sent mail 30 June, again automatically confirmed. Paid R 819.33 on 18 July 2026. Now again you send me a invoice for 819.33 with threat of stopping service. What must I do to action my request for cancellation??? Now I have been threatened with suspension. Please help.