Unhappy customer

On the 27th May around 4:24pm I received a text from vodacom that says if I recharge with R20 or more I am going to receive 100 Voda bucks, I did that. 28th I recharge with R15 and on the 29th with R5 airtime in total its R20 I did not receive my 100 Voda bucks. Friday I called them I spoke to Maria from the voda bucks department she advised me to wait atleast 72hours they will appear and I waited. Monday I called again and explained my story to Nelisiwe told her that I haven't received my vodabucks, she tole me to sent her the proof of the sms vodacom sent I did that it was a holiday on Monday she said they will get back to me starting from Tuesday since Monday it was a holiday I haven't herd anything from them they just went awol on me, I just want my 100 vodabucks because I have paid for them. How can they advertise something and failed to deliver to a customer because to me thats a *****. I have a proof of the sms and a proof of airtime purchase.