Refusing to cancel my unauthorized upgrade.

Someone called me asking me if i wanted to do an upgrade on my contract phone which sounded to good to be true and i was told on the Ts and Cs that they deliver their agreement papers to my address and only then they will activate my upgrade but to my surprise, i was upgraded without even getting those papers to sign and now when i call Vodacom to query that, they say i cannot cancel because it is way pass the 14 day cancellation process. I think that is not fare because i didn't even agree to that and i was told that upon them receiving back their signed documents, i will have 14 days to cancel and so i set and relaxed coz no papers were delivered to me to singed. This is wrong and will cancel all my contrasts with Vodacom if they do not fix this. So not fare.