Advertised deal online but not avaliable

hi Was looking on the Telkom website http://secure.telkom.co.za/today/shop/plan/internet-starter-pack/ there is a deal with a mi-fi router for R349 and R649, can get them in store when i phoned to enquire about it they don't do that deal even though it advertised, this is shocking how can you advertise something you no going to sell customer's