I want them to cancel it and reverse the money they deducted

app**** for rooter in August from MTN I told them that Im applying it for my parents I even given them their address and they delivered it but rooster didn't have network I tried it at my place and also a my parents place still it was not working I call them several regarding the issue but I was not assisted until I decide to cancel it I call them to cancel they told me that I must go to MTN store I went to Vereeniging they told me there's no network I then went to Vaal Mall to cancel it and return the rooter which I did the lady gave me a paper with Ref on it I then received a msg that MTN received their rooter but to my surprise when I receive the msg it was I took it for repair I called them again for clarity because I wanted to cancel it they told me is not cancelled I asked them to cancel they said they don't do it over the phone I must go to MTN store again I went to Vaal Mall again the told me that they don't do cancellation in store now. A lady from collection called me explained to her my story she said she's going to check and she will call me she never did now their collection department they are busy calling regarding the areas and I ve cancelled it