Suspicious account shipping address in my account

I recently logged into my account and noticed in global settings that there was a shipping address I did not recognize. When I googled the location on google maps, it turned out to be a shopping mall. TMobile could not explain how that address was set as my default account, or whether anything was shipped to that account, including bills. I'd like to contact the fraud department, but there's no direct link to them. Suggestions on how to proceed here?