false advertising

I am truly annoyed with Vodacom. They advertise, get a new contract and choose between a few gifts. It looked very rewarding to take out a contract so I did. I chose a selfie stick as I have a powerbank already. Today, two weeks after I got the contract, I get told the selfie stick is not been made anymore. What????? Seriously? Then I get told they offering you something better, a powerbank....hello, I didn't want it in the first place so who are you trying to fool? Why would I want another one. I still want my selfie stick or a phone cover but I DO NOT WANT A POWERBANK. please can someone sort this out as its not nice to wait for something for two weeks and then get told its discontinued!!!