Hello Mark and welcome to JustAnswers.
As for your question, the Time Warner site says that they choose the number given to you. IF though you do not want this number, it is best to contact them directly as you can talk to a representative who can help in possibly getting the number you want.
Information to contact Time Warner can be found here in this link:
I hope the information provided will help in getting your old phone number back. If you could take a moment to rate my assistance so that I can receive credit for helping you as well as allow me to assist others on our site.