Hi, we have a vodafone smart n8 phone, and the last couple of months we have been losing credit for some reason. It is just a basic prepay and we just top it up $20 whenever it is needed (usually every month or two - I keep records). This year it seemingly lost credit over xmas period (was topped up on 20th Dec when the phone was switched off for 4 weeks as its a work phone, topped up on 4th Feb, then had to again on 8th Feb, and now its due again 26th Feb. The data was turned on, but only had very minimal use from app updates. And total calls dialled out for this year was about 14, and they are only a minute or two long.