Can't even get the basics right in a contract

MTN completely messes up my contract, delivers the wrong device and now expects me to pay for a 24month contract. Everything I asked for was recorded for goodness sake. I've given back your device and sim at a store even though MTN delivered the wrong device, so shove your contract. I've sent 3 emails with no response. It's absurd that the only alternative in South Africa is Vodacom, but at least they respond.