Wrong Phone Delivered

on the 26/09/2017 got a call from cell c for cellphone contract, of which i opted for Samsung J5 R 199 contract, which they promised to deliver the next day but wasn't. delivered on the 28/09/2017 only to find it's a wrong phone, asked the driver to take it back but he refused and told me to call cell c first. called cell c and they said it will be fetched the next day. 29/09/2017 i called to find out how far they are, i was then informed it could take up to 7 working days. now i have to carry the phone around till they decide to come get it. i want my contract with them to be cancelled with immediate effect for bad service received.