HELP I am about to forfeit my data

<p>I purchased a 2 gig data because I was downloading a lot of documents. Before I finished downloading, left with 143Mb I realised that I will not ne able to complete my next download. I thend decided to purchase 3gig more to avoid my download being disrupted.</p> <p>Instead of my initial data being used first and then the addition, the 143mb is still available, and the data that is running is the latest 3 gig.</p> <p>This morning I called and I was told that vodacom terms and conditions is "last in - first out"</p> <p>I requested that someone explain to me why this is happening like that because what that means is that I am going to forfeit my 143mb as it is about to expire on 5 September.</p> <p>The one that is running expires on 17 September.</p> <p>I spoke to 5 people so far. The last conversation was with a customer service consultant who told me to hold on as she consults with her manager.</p> <p>Music was played for over 30 minutes until I hung up.</p> <p>I just need someone to explain to me what is going on. PLEASE</p>