Refusal to cancel upgrade

My wife and i went to Vodashop in Springs to upgrade her cellphone and also to take out an extra cellphone contract. this was 21st February 2015. Resenda was the sales lady that helped us and did the upgrade first.<br> after she did the upgrade she then told me that Vodacom declined the second contract. So i decided to cancel the upgrade as well. I then took the form for the upgrade and scratched it out and also wrote on each paper ( cancel). i know any contract has got a cool down period and this contract was cancelled within 10 minutes. Still they went ahead and did the upgrade and my wife can't use her phone eversince. i have spoken to Eben the shop manager and he just refuses to cancel the upgrade. i did not even take the new upgraded phone that day and yesterday i was contacted to come and collect the phone as they will not cancel.