Cancellation of service (Internet/ WiFi)

I have cancelled my service with VOX on 01 April 2021. In addition I was advised that I must submit the cancellation before 4pm or close of business in order for VOX to accept the cancellation and not be held liable for another payment. The reason for cancellation was due to moving premises. The cancellation was submitted and accepted by Vox with no penalties. I received an email as confirmation. A few weeks after the cancellation I received a statement where I was billed for 2 lines (the old address and the new address) and as such I was billed double. I immediately enquired why I’m being billed for 2 lines. The response was that my cancellation was outside the 30 calendar days - this after the cancellation was indeed accepted. The person I dealt with told me that she will have to request the call recordings in order to verify. To date I have had no luck in response or any feedback with regard to the so-called recordings. The double payment was deducted - so they couldn’t care less. When I threatened to cancel the new line - she politely told me that I will be held liable for an additional R2000 for such cancellation. Today, 10 May 2021 I was advised that the occupants at the previous address is unable to connect their internet service (WiFi) as the line is still active. I yet again enquirer with Vox and I was told that the service/ line will only be terminated at the end of May 2021. This after I have cancelled the line on 01 April 2021. The very same lady asked me via email - Do you want me to cancel the line before 31 May 2021? How is this feasible for anyone other than Vox capitalizing on the subscription charges!!! This is an absolute *******!! I regret continuing my service with VOX.