It looks like someone else might be using your account

everytime i log in to xbox live on the computer i get this message : It looks like someone else might be using your account: and just recently i can't sign into xbox live on my xbox. i have reset my passwords and filled out an account recovery form and now i have deleted my xbox live account of my xbox and its cache like xbox live support has told me to do and now i am unable to to get it back!! i have done just about everything.  i have called multiple times but xbox live support cant help. i am a paying customer.  i dont understand why i am having so much trouble to get my account back to normal.  is there anyway i can get it back?