contract upgrade

my wife and i have a total of 5 contracts with cell c. one of those contracts is my mobile phone which is due for upgrade and im paying R840 a month. I took time off work to go and upgrade my contract as I found a deal online that I liked. the deal I was looking to take was R479/month plus i requested paying an additional R80 for the smart watch which was advertised. my upgraded contract would have come to a total of R559/month which is R281 less than my existing contract. when i requested for this upgrade, i was informed that i qualify for the phone but not the watch which was advertised and is R80 extra. i got no explanation from the consultant and this makes no sense to me. After trying to get an explanation, i was then informed that theres no stock for the watch yet it was advertised, which is now false advertising. i then told the consutant that i am going to cancel all 5 of my contracts with cell c and they couldnt care less. cell c should not be false advertising as it will draw customers away from them.