Vox poor service

I had an issue about Vox in whiteriver Mpumalanga and I did report it here and it was fixed after 2 days yes I'm happy for now until I receive my statement today that I'm owing R4197.00 which I'm not aware of.I called them to find since they didn't bother to call me or notify me,2 years ago I subscribe with them they send people to install everything including router and weeks later I rent Deco booster to them since my house was big and the wall struggling with internet.I rented it for the whole 2 years and I moved from that house to the small apartment and I gave them month notice and my account was fine ,also took another one which I took to one of their agent and she said they will come and collect the router and the decor which I agree but no one has ever called me regarding that issue until today.So today I receive my statement find out I'm owing R4000+ and I called for clarity then they told me it's for the router and deco I should have returned it so I ask where since no one communicated with me and their staff is still with me and the agent told me they send courier guy to come and fetch it and I told them there's nothing to collect and I can't remember having that conversation with anyone regarding Vox ,so now they to clear that credit I have to return it myself so my fear now is what it those thing doesn't reach to them and it's gonna be much fault and left with credit which they failed to fixed.Their staff is with me and I send them pictures still those agent refuse said I must send it myself as if I have refuse with them.Their service must questions and they don't communicate that just do as they want and I been with them ever since and the continue to disappoint me again