VODACOM NORTHGATE IS USELESS!!!

I have taken out a contract whereby i get to choose a gift(headphones) with my phone, i have done so and Vodacom advised there is no stock, THAT WAS JANUARY 2015 until i have not received anything, i went to the store about 5 times and spoke to 5 different agents who advised \they will sort out the issue"and call me back but never did...I WANT THIS RESOLVED IMMEDIATELY"