I have been phone for an hour now to helpline 0800800 150 and still listening to the we are very busy messages. The BT website says that they are open - are they at weekends. Assume if not I would get a different message!
customer service is open just as you have found exceptionally busy especially at weekends
Perhaps you can get some help here, depending upon the problem. You may even be provided with an alternative phone number.
Care to enlighten the forum volunteers?