I had applied for a change from 'postpaid' to 'prepaid' for a particular number more than a month back and nothing has happened so far. In fact, I receive another bill for not using the number at all!
And this is the last fiasco! They release an ad for free 3G service. I do the needful and it is almost a week and nothing has happened!
Happy to help, I can help you Vodafone!
Sent on my BlackBerry® from Vodafone