VODACOM Ripping me off on forced contract

Vodacom can w******* customers, after getting a call offering me a gadget for a month to month I went online to pick a gadget only the gadget not to be linked to the open month to month contract. Vodacom opened a new line. I alerted Vodacom of this unlinked gadget December within 2weeks of the new gadget..they promised to fetch the gadget cancelled the contract. Courier came 23 when workplace was closed to find I had left for holidays. January talking to the to fetch the gadget they didn't fetch it until Early March when I got a courier that called fetching the gadget. I took GADGET / SIM back to Vodacom on RAM code COL***1. March Vodacom charged me the whole returned monthly fee. Come now in April Vodacom charges me a line fee for a GADGET & SIM they took back. How is that so? Why is Vodacom only taking the gadget with clarification on standing line fee ? I don't need their extra line as I have my open month to month contract. All I needed was a gadget linked to that open line but instead Vodacom opened a new line which I am forced to pay for 2 years.. I wanted the gadget linked to my existing line, but now I a ********** my Vodacom to have 2 lines charges & worse they have taken back the gadget & sim card.. mxmmm .