Vox telecom is Billing me every month for something I never used

They are charging me every month for a service I never used... they are saying I owe the 4k they charge me R600 every month for something I rejected numerous times.. they Installed their fibre at my house with incomplete equipment.. the agent said that I will recieve the router during the week of which it never came. I waited for a month still no router and mind you they said that they do free installation and the first month you use data for free.. yes they installed for free but never got the chance to use the data as there was no router so how am I owing them? Vox falls under openserve and telkom managed to help me with the issue as I'm now using it and we even had an agreement.. I don't understand how vox works how can you bill someone who kept rejecting? On their website there are offer for unlimited fires starting from R200 but when u talk to their agents they tell you they only have only one offer which is the R599.. they are the biggest **** ever