Contract not as advertised

I upgraded my contract to Smart S+ Top up together with a data contract which cost R100 for 3.64Gb at Vodacom data store in Claremont. I asked the shop assistant if I could get the data plan as well (since you only get 350Mb with Smart S) and he said that I could. He then suggested that I switch to Top Up instead of an open line because that way I won't incur out of bundle charges. At this point I thought that the contract was for 50 min, 50 sms', 350Mb and 3.64Gb per month. When my plan was switched on 1Dec I did not receive the 3.64Gb. I went back to the store to find out why only to be told that that data deal was only for open plan contracts. Now at no point when I signed up for my contract was I informed of us. If I was I would have chosen a different contract and handset. The person I spoke to then said they would send my information to head office and call me back. That was on Saturday 1Dec. No one called me back. It was up to me to call them. On Monday I called again and I spoke to the person who helped me upgrade my contract. I said that I would be willing to take one of your new data deals and have that added to my contract (you're advertising 2 year contract of 5Gb for R99) and he said that he would speak to his manager and call me back. He did not call me back. At this point I was getting extremely annoyed and frustrated with the service that I was receiving. I went back to the store today (5 Dec) and was told that I can migrate to the 5Gb plan after 3 months but that a migration fee might apply. I absolutely refuse to pay any migration fee as I am not at fault. If the Vodacom employee had done his job I wouldn't be in this mess to begin with. I shouldn't have to pay for his mistake. I have been a loyal customer for more than 10 years. This whole episode has me considering moving to a different network when my contract expires. I am not at all happy.