The worst service provider in handling customer issues

Vox telecom has the worst customer service, i have app**** for fibre and they never came to finalise installation of equipment and i ended up cancelling and they still charged me for a service i never used that was in January 2025 and over 4 months later i am receiving emails of charges on the account that is now over R 2000 for a service i never used and the consultant keeps saying the matter is under investigation when i have given all evidence of my cancellation and due to their poor service they did not do the cancellation on their side and they are sending me emails saying they will hand over my account to debt collectors while this was due to their incompetence.