Problems with O2 Telefonica

Have you had problems closing an account with O2 Telefonica? I have found that they are reluctant to respond to any questions that have been raised and will not even provide me with a final balance to be made on the two accounts that I have. Information that I have been provided with is contradictory to former statements that they have made. I am sure that I am not the only one in this position and they ought to be held responsible for the way in which they act