Utter Nonsense!

I have recently taken out a contract with Mtn via their web services, I have received the device within 2 days however it was suppose to come with a watch, I have contacted Mtn to enquire about the watch and was said that it does not come with one, I then proceeded to cancel the contract within the 7 day cooling off period, I have spoken with someone who ensured that the contract would be canceled and I was still within the 7 day cooling off period so I did not have to pay any other fees. The device was dropped off and returned. Now i have received various emails stating that the contract is not canceled and I am liable to pay for the next 36 months I do not even have the device, the sim or even the watch, is this how Mtn tricks people into contracts?