I have an extra charge of 50 cents (no, not a lot) for "Additional Charges" . When I look at the calls made or received I see one call in the middle of the cycle is randomly $0.50. It is on a Sunday (nights and weekends free) to a local number and I did not exceed my 100 minutes for the cycle. Other calls to that number have no charge. Any ideas what is going on or how to get it changed? Thanks.