data disappearing

<p>I am really disappointed by Vodacom. I have been a client of theirs for a while. I generally spend about 2 gb of data a month. this month I bought 5 gigs and it finished before the 20th. I then purchased another gig which is now depleted. I would like an explanation as to how this is possible, I have invested more than 6 gigs and it has not lasted 30 days. I really don't understand. this is ****************. please, can they contact me to sort this out?</p>