said by SoonerAl:
Are you trying to add services by calling TW or have you gone to a physical TW store to add services? If its the former you may have better luck visiting a physical TW store.
I've tried by phone and I agree going in will be easier. However I ran into a sales rep for TW and he checked on it for me and when I called him he said his boss said it wouldn't be possible.
I'll go by their office tomorrow and find out for sure.