Firstly, the diffrence is an hour, I don't think that it is a considerable amount of time which you are set to lose. BT is a obviously, very large company and I am sure that if you found a solicitor who was daft enough to waste his time and take your case on, you would end up walking away from court, owing alot of money in legal fee's. Not to mention how much time you would have wasted, It is one of them things which, however annoyed you may find it, is alot more trouble than it's worth. On a slightly more positive note which you will probablly prefer to the one above, ring BT and voice your point, if the customer service agent fail's to provide you with the answer/soloution which you are satisfied with then, ask to be transferred to somebody whom is superiour to them, ie, preferablly the manager.
Try at all costs to avoid them getting someone to call you back, as this is usually something which never happens! (same with most places).
Hope this gives you some kind of answer in which you was hoping for.
Lastly, I am a virgin media customer and upon becoming a customer with them, the service seemed of slightly poor quality for the amount that the bill's were. (Usually the phone calls alone was costing anything from £50 and upwards, therefore I decided to ring customer services and see if anything could be improved, they tried to offer me the XXL package which I was not interested in, mainly due to the fact I am not a big TV watcher, more of a net sufer. I then explained to the agent that I was not happy with the service I was getting, especially for the amount of money I was spending. He then transferred me onto a manager, who gave me, Large TV package, Unlimited 01,02 and 03 calls at all times, and broadband, for £19.99 a month. This has continued at the same price for the past 2.5 yrs.
End of essay, haha!