TIME SENSITIVE - MASSIVE BILLING OVERSIGHT

I have purchased two of the £5 cards and just received my bill from o2. Absolutely none of my calls were discounted and you have charged for all the attempts when the service was down. On one occasion I had to redial into your service 9 times to get a conneciton and you put these through as 9 x £1.10. Before the start of each call to the USA I was given how many minutes I had left for each call and yet I have been charged normal roaming rates for each call. You have provided cheated me out of a service and I need my bill paying immediately.