Cell C incompetence

I'm sick of cell C incompetence I ordered a device online only to be sent the cheaper of the 2 options at the price of the more expensive option on recieving the incorrect device I immediately called and cancelled this contract due to the fact that they did not have the one I wanted.they collected within a day or 2.Thought that the end of it.Come month end I get debited for this contract. I was in holiday in the states I emailed them immediately thinking clerical error was told to cancel I must wait until I back in SA to cancel due to wanting a security check before they can refund.I was in states a month so by the end of next month I get debited again.I emailed customer care to rectify only to be told by operator can't be cancelled as device was exchanged and collected if I understand correctly from cell C canal walk in Capetown, I live in Durban.I don't understand how this could be signed for as canal walk is not only more than 1000 km away from me and as the soulless operator whose only interest was security check and when pressed for answers she put the phone down on me.I have been a cell C customer for plus minus 20 years I cannot believe this debiting me for a device or contract I don't have.