Has anyone else had O2 overcharge them by messing up the free minutes usage on their monthly tariff? It has happended a few times to me over the past few months. Basically my billing date is 20th of each month so my 100 free minutes runs from 20th to 19th of the next month. This has been confirmed to me in writing. The itemised secion of my bill always seems to go from around 18th of the month so it includes calls which should be in the previous month. If I make any long calls in the last few days of the month they add these to my call total so it exceeds 100 minutes and I get charged. I only noticed the first time as I got charged £11 for calls when I knew I had not gone over. I have no idea how many times in the past I may have been charged a couple of pounds extra that I would not notice. O2 have refunded me each time but it is a bit poor that they cannot work it out properly. I now have to check my bill each month to see if I have been overcharged.