Vodacom false advertising

After a long while I decided to start the services of Vodacom by purchasing 1gig data. Coming to an end of the data I receive a message that I can buy 2gig for R205 before midnight so yes I chose to take them up on the offer by dialling *124# and I get a message that I have insufficient funds. Well No, I have more than enough funds for this offer. I phoned customercare and was told to turn off all sessions, my data and turn the phone off, but nothing worked. Honestly I think this is vodacoms tactic to get you to load money on your sim card by purchasing airtime. Well I am done with Vodacom again.....I will be going back to my previous provider.