Wrong sim delivered

Sales person by the name of Gregory called me regarding a phone and i accepted the offer, phone was delivered 08/10/2015, however the wrong sim was delivered, i went to mtn to enquire if they could assist i was told that i would be charged for the new sim, and they advised i should call mobile plus, which i did and was told to go back to mtn as they are the network provideers and they only sold the phone to me, which is did again and they guy at mtn called mobile plus, mobile plus advised that they will deliver the new sim card, im still waiting for the card, yesterdat i recv a sms that my phone has been activated but i dont have a sim, i then called again to enquire reagrding the msg i recv, the lady assist me but dropped the phone i then had to call again, a guy by the name of ION/EOn assisted me and he said he will logg it on the system as it doesnt reflect there, i said id rather cancell the contract if this is the type of service that im getting, no-one called me since friday i had to call them everytime, i asked him hw much are they gona charge me if i cancell cause in the contract it states something like dat and i wont pay, he said why am i askin cause i said i wnt pay