Offer that doesn't exist

My contract with Cell c ended 10 January so I went on to \ pay as you go". I received an sms that offered me unlimited whatsapp for R5 for 30 days. I accepted the offer and the R5 was taken off my balance. I also received a confirmation sms saying the bundle had been activated but it didn't reflect on my phone. I then phoned Customer services only to be told that it doesn't work on a Blackberry curve. So why was the R5 deducted from my balance? It is downright thievery !!!!! Last time I fall for Cell c \""specials\"". Also i was now looking to take out a new contract but it certainly will not be with Cell c"""