Vox - terrible service and incorrect billing

We moved from CT to Pretoria a year ago so changed contract to Pretoria and got a new modem . Dec last year someone called to say they need to fetch the old modem. I had no idea where it was 8 months after moving. The lady told me they had issues with their previous courier company which is why it has taken so long. She said let’s wait till Jan to give me time to find . Which I did but I never heard from them again . Suddenly I receive an invoice for R2000. When I called I had a very rude lady on the phone who said it is what it is and I must just pay it. When I got upset she put the phone down. I have no idea where to take th A modem or how to get this invoice reversed as the consultant refused to assist. I will be canceling my whole co Tracy as this is disgusting service. They can call me on ***. Keri Louw