thanks for that!

When i asked for my copy bank statements i received a letter saying that they were under no obligation to send my statements and were refusing my request. Two days later I received every single statement (communication error perhaps) I figured out the sum owed and requested it back in full, including interest. They responded saying that they were looking into the matter. Two weeks later they have written back to say they will have an answer for me by 4 September 2006. Should i write to say this is unacceptable or just let them deal with the matter at their own pace? Are they trying to find a loophole that they can exploit so that they dont have to pay? Thanlks