O2

I have a screenshot of a msg that o2 sent me saying my account balance was £44.47 last Fri 19th nov , when I topped up.A few days later it said £24 ,my bolt on was taken and I sent one msg,the app won’t show my balance,I use free Wi-Fi all the time ,...

My WiFi is the virgin 200 mb ,My mobile data is switched off ,My phone is connected perfectly to the WiFi?Why was I charged for this text sent 5 mins ago,This has happened many times before, just not had time to deal with this.