Debited for no reason

I’m disappointed in Webafrica. I sold my house last year and the new owner took ownership of the WiFi services , I transferred the service to him and this was in September 2023. This morning my account was debited with R1900 and when I follow up with webafrica they told me I cancelled the service and did not return router whereas the service was transferred. I ask the new owner if he is still using the service and he is and paying every month . Webafrica is doing me wrong and they need to fix this urgently or I will escalate to the ombudsman.