Monthly carried over airtime minutes lost

My contract gives me 250 minutes airtime(voice) a month and what ever is left over will expire the next month. <br> <br> The problem with this is that you first have to use your current months minutes before last months minutes will kick in !!. I only realized this now after all this time.<br> <br> I see this as a ********* business practice from Vodacom and totally disagree with the way they are cheating the customer out of paid airtime.<br> <br>