I am pleased to say that once Talk Talks Executive became aware of the problem not only did they apologise but credited the prompt payment discount I should have had. This problem was due to the e-mail they send out advising that your bill is now available on-line was sent out late on 27th of May instead of 23rd. If you pay within 24hrs you get the prompt payment discount which there system allows you to do. But because the notification was sent out late there was nothing on the system which allowed for this.
Talk Talk are a good concern and very helpful if you can get your concerns to the right people. I am pleased with the outcome and the steps being taken to prevent this happening in the future something which will help others as well as me.