horrible service from mweb and theft

i had decided to sign up for a deal with mweb on the 29th of feb and an mtn sim was sent to me and was advised that to activate sim i need to put it in a devise so i did so now after 24 to 48 hours to my Suprise services were not connected and i tried to call mweb immediately so i held on for over 30 min as there answering machine keeps saying you are caller no 6 and when an agent answers they keep silent then drop the line i did this for 3 consecutive day untill i decided that i dont want anithing to do with mweb .now when i emailed the sales person who assistend me she called me back and connected me to the relevent parties to cancel . but when i wanted to cancel i was told that i cant get a refund as they have no proof of my calls i told the gentlement that how are you gona have a call if my calls wher not taken ? so now mweb is refusing to refund me but they did not render any services for me and they can see on there systerms that there was no service rendered . now they say that they will cancel but they will still charge me as i did not serve a notice . how do u serve notice with no services ? i want my money back or i will take matter to court